"He shared that when you're sweating and don't have time to take a shower, you just take a baby wipe and rub it under your armpits," Pitt's costar and pal Eli Roth told PEOPLE at Saturday's Spike TV Guys Choice 2009 in Los Angeles, set to air on the cable network June 21 at 10 p.m.
"After a scene, Brad had to get next to me for a close-up shot, and he said, 'Damn, you're ripe,' " recalls Roth, 37. "I said, 'I didn’t have time to shower.' He said, 'Baby wipes, man, baby wipes.' "
When it came to Pitt's pits, Roth said the leading man explained, "I got six kids. All you've got to do is just take them, a couple quick wipes under the pits." Pitt further said, "Man, I'm getting [peed] on all day. I don't have time to take a shower."
"I thought that was the greatest tip," says Roth, who took the advice to heart. "My character is called the Bear Jew. If I ever started to smell like a bear, I would just use a couple baby wipes under the armpits, and it made it safe for everyone else to act around me."
Awesome AngelinaRoth, Pitt and company recently returned from the Cannes Film Festival, where they promoted their movie, which hits U.S. theaters in August. While in France, Roth was seen partying with Pitt and Angelina Jolie. Jolie, Roth says, "is awesome, totally cool," just like Pitt.
"He's such a funny guy. He has a great sense of humor, and he's so into it. He's really there to have a great time. Now, he's at the point in his career where he's the biggest movie star in the world, he can do whatever he wants, so when he's there, he just wants to have a great time."
Roth – who's built his own cult following as the director of such horror flicks as Hostel and Cabin Fever – is also quick to say Pitt was very generous with his time.
"I remember the first day, he taught me a lot of acting tricks," Roth says. "We all wanted to ask him about Kalifornia, Fight Club and True Romance, and he was so cool to talk about all that stuff with us. Right from the first day, we were all a little shy. But then somebody asked him about 12 Monkeys, and he talked about everything."