Every time I've harassed some loser at a 3CP game nobody knew I was doing it except the target. I do real subtle things that nobody else notices. It's not like I'm standing there throwing drinks on them. I do things like breathe on them, tap on their chair, fart, etc.. One time I was on a game (playing from spot 3) trying to get rid of the guy playing spots 1 and 2, and kept talking to him, and kept asking to play his hands that he's folding (he kept saying no and was getting annoyed by it, so I kept asking). Just standing very close to someone for a while makes them uneasy. Yes, I HAVE drawn heat doing this one time, and in that case I left. Other times the tactics didn't work and the ploppy kept playing, but there are times when I've gotten them to change their mind about buying in again at that table (They would do something like pull out their wallet/more chips, then look at me, then decide to go to another table or something). If people tell me to go away and start drawing attention to the fact I'm standing there, then I'll leave, that's happened one time. Most ploppies just keep looking at me uncomfortably but don't say anything.
Funny thing is for stronger games like BJ it's actually easier to get rid of someone. I've run people off BJ games real fast. Basic strategy for getting rid of a target at BJ, is every time they win a hand I change the # of hands I play (play 1 hand, play 2 hands, sit out). I told some lady she was stupid for standing on her soft 18 vs dealer 10 (dealer ended up having 20) and that's why she's losing, and she got real pissed and left immediately.