Billy Mays’ Son Gives Rare Look Inside Late OxiClean Founder’s Life 15 Years After His Sudden Death (Exclusive)

• Billy Mays’ son, Billy Mays III, has worked hard to keep his dad’s memory alive in the 15 years since his death
• The 37-year-old tells PEOPLE what it was like to witness his dad’s rise to fame and what his legacy has become
• Billy Mays died at 50 in 2009

Billy Mays III shared a special bond with his father.

The son of the late iconic pitchman Billy Mays tells PEOPLE that although he didn’t grow up with his dad in his life every day as a child, they later developed a close relationship.

“My parents were divorced. I lived with my mom in Pittsburgh, Pennsylvania, and spent summers with my dad in Florida. I would also see him when he would come to town. He was like a traveling pitchman for years and years, and so I would see him every time he would come through for the Pittsburgh home show,” Billy tells PEOPLE exclusively of his father.

Billy remembers “playing with X-Men toys under the booth while my dad was pitching” at conventions and later, visiting his dad during marathon stints at the Home Shopping Network. Billy was in high school when his dad started becoming a bonafide public figure.

“He was definitely known by then because some of the big commercials had come out in 2000. I was a freshman in high school then, and he was very well-known in our town. It was a big thing that people were picking up. By the time I was in college, it definitely changed to him being very famous.”

Billy recalled a teacher who would call his name during attendance and then ask, “Like the guy on TV?”

“I would always say, ‘Never heard of him,’ and the rest of my class would laugh because they knew who he was and who I was.”

Despite the joke, Billy says he was “excited” about his father’s fame.

“It was cool that my dad was doing his thing. He was beloved by the common man because that’s where he came from. He started to make it in his career when he was in his 40s. He was a hard-working dude. A lot of the time, I feel like I enjoyed it.”

The two would get to spend more time together when Billy graduated high school and moved to Florida, both for college and to be closer to his dad.

“Eventually, after college, I moved into his house for about two or three years. It turned out to be the last five years of his life that I spent with him. We were getting to know each other as adults because we didn’t spend as much time together as dads and sons do growing up,” he says.

“We watched a lot of movies together in that time that I was with him. When I lived in Florida, he had a little eight-seat movie theater in his house that he had built,” Billy recalls.

“I took that over when I moved in, but we would watch a lot of movies. I remember his favorite movie of all time was Gladiator with Russell Crowe. We watched that a couple of times in there.”

Billy says there were even a few “perks” he got to enjoy as Billy Mays’ son. “I always thought it was a big deal when he would bring me on camera. Sometimes we’d go and crash other people’s live demonstrations, try the bread or whatever they were making,” he says, laughing.

As an adult, Billy got into production assistant work, which his dad encouraged.

“I started out on his shoots. He brought me in one day after I was out of college and he basically told the producer to put me to work — a true nepo baby in the infomercial world,” he jokes. “I started out and I had to actually work hard. There was no pressure on them to keep hiring me after it was not my dad’s shoots anymore, but at that point I really ended up liking the industry and moved outside of the sphere of infomercials.”

At the same time, Billy was watching Pitchmen, his dad’s reality series with Sully, former business partner [Anthony ‘Sully’ Sullivan], unfold.

“I got to work on the whole Pitchmen season, which was basically them filming us working in that year before he died,” he recalls.

“There’s one episode where I was heavily featured, and I got to direct my dad in a local commercial for a pizza shop that was his brother-in-law’s restaurant in Florida. I ended up directing it and the episode was called ‘A Tale of Three Billies’ and it’s about me and my dad and my grandfather, Billy Mays I. It was fun working with my dad all the time, but it was really cool working with him in that way.”

Over the last few years, Billy shifted from his production work to focusing on music. He fell in love with exploring instruments in high school, with the support of both his mom and dad.

“My parents got along really well despite being divorced. They both really supported the things I cared about, and me wanting to play music. My dad bought me a guitar and my mom took me to guitar lessons, and I loved it. I have music that I made my junior year of high school still,” he says.

“Now, I play all kinds of different shows and tour around when I can and release albums. It’s my thing.”

There was a lot of his dad’s life that fans would have never expected, but one thing everyone did get to see was his dedication to his craft.

“My dad was always a workaholic. That was his thing, just grinding his whole life. He didn’t stop that when he became famous,” Billy says.

“There just became more work to do. He also had a daughter, my half-sister, who was 3 when he died. So at that time, he was very much just about family time and work time.”

The side many didn’t get to see? “He was very soft spoken,” Billy says of his dad.

“A lot of people who knew him in the production industry knew he was a quiet kind of guy. He was very friendly, but when he’d speak, he was just calm. He wasn’t ever really rowdy the way his commercial persona was.”

“He was also a really generous person, probably to a fault. For instance, people would always ask him for free OxiClean. The funny thing is that once OxiClean became acquired by a bigger company, it was much harder to get OxiClean for free because it was corporate now,” he explains.

“He wouldn’t tell anyone that, though. He would just go out and buy it and tell them he got it for free. So there’d be days when he’d go to the store and get 20 tubs of OxiClean to give out and tell people it was free from the company.”

One of Billy’s most cherished father-son moments was meeting Conan O’Brien with his dad, just a week before the pitchman’s unexpected death. The 50-year-old was pronounced dead on the morning of Sunday, June 18, 2009, after being found by his wife, Deborah Mays, authorities told PEOPLE at the time.

“The week before he died, he was invited to be a guest on The Tonight Show, in the brief period Conan was the host,” he recalls. “He had already been on The Tonight Show with Jay Leno a couple of times.”

A Conan fan, he made his dad promise to bring him if the opportunity ever arose. And when it did, the proud dad followed through.

“When he got the call for Conan, he literally called me and he’s like, ‘I got you a ticket. We’re going to see Conan,’ ” he says.

“They were there to promote their reality show and I got to hang out backstage. The other guest was Lisa Kudrow from Friends, and Elvis Costello was the musical guest, so we got to meet all of them. But meeting Conan was the best thing.”

He continues, “I have a picture of me and my dad and Conan and, of course, Andy Richter and the band. It was one of the most exciting nights of my life, and the last time I saw him.”

Billy is proud to see OxiClean’s staying power, noting it’s a product he still uses in his own home to this day.

“It genuinely is a household name product. My daughter is 3, so she’s constantly staining her clothes and I literally just spray some on. and throw it in the washer. There were a lot of products that he worked on,” he says.

Billy is also keeping his dad’s legacy alive, both at home and online at BillyMays.org, a fan community and tribute space.

“It’s funny because my daughter doesn’t really know. The sad thing is both of her grandfathers are dead, so she doesn’t have any grandpas, but she has two grandmas. We tell her about her grandpas a lot,” he says.

“For a while there, when she turned 3, she would always bring them up. She’d be sad out of nowhere, and you’d ask her, and she would be like, ‘I’m just thinking about my grandpas.’ And we’d be like, ‘Oh, that’s okay,’ and show her pictures,” Billy says.

“The cool thing is she has a great-grandpa. My dad’s dad is in Pittsburgh and she’s gotten to see him a couple of times.”

Billy has memories of his dad everywhere and notes, “It’s funny because we have stuff hanging everywhere, but I don’t even know if she realizes that’s her grandpa yet. Eventually, one day, I’m going to show her all the commercials, and that’ll be a lot of fun for her to see.”