I have found something to say that gets people to fold.
This works best in a showdown, after the river, in person. If someone is taking a long time to decide on a call, I have said. "if you fold, I'll still show you."
It bugs them, but it tells them that I know I have the better hand and I want show it off.
I feel like a total ass when I say it. But it seems effective for those people who are OK with feeling like asses when they are stacking chips.