It's just straight up gross as hell. First time I ever did dip, it was stolen. Friends and I were walking through Wal-Mart, and that was back when you could grab your own tobacco products, and my dude had this system where he'd grab two cans, and then we'd go shopping, and he'd open one of them, then on the way out, he'd put the other one back. It was stupid as hell, but he got away with it.
Anyway, we left the building, and we dipped while we were walking through the parking lot. Behind the buildings, another buddy made us stop for a minute, "I dipped too much, hold up," and threw up all over the pavement for miles.
The second time I dipped probably wasn't for five or ten years after that. By that time, it was with a fellow adult, and it was simply a way to get tobacco in a non-smoking apartment while playing WOW. Still gross, though, and I stopped almost immediately.