I found this as an addendum to a great article by grapsfan on Pocket Fives. It was written by Jennifear and I consider this to be absolute gold:
I'm not much of a chatter, and you won't find this advice anywhere in a book, because it doesn't promote the game. If you want to tangle in the chatbox and have a little fun, then I have one word for ya:
If you want to tilt someone in a nasty fashion, use an argument devoid of logic. The reaction you get is priceless. When you beat KK with A4, then "it's about time I won a coinflip", or "no aces flopped last hand, so I felt they would hit this hand".... this even works better if the flop last time contained an ace.
"It was suited." "It wasn't suited so I had TWO chances to hit a flush, not just one." "I had a feeling." "I have all the chips now, so I must be better than you." These one-liners work.
If they can't beat your argument with logic, they will become very frustrated and tilty. Plus you aren't getting mad, your goal is now truly to get them upset, and use your newfound image to your advantage, so you won't get caught up in defending your plays. One last word of advice if you are going to use the chatbox as a weapon: Fight right, nice left. You want the player on your right to call your 3-bet value raise out of frustration, but you want to be able to continue to steal from the player on your left.