It depends.
Normally I don't show my hands, bluffing or stomping. However, if I've been beating the hell out of a chipleader with strong hands, and afterwards I get a pot from a good bluff I may show the bluff to try and tilt him/her. Oh, and as I'm not a constant bluffer (god I hate those) it also helps me to set them to call a strong hand next time. Misleading the villain (or the hero, as this is a cruel thing to do
) is really helpful, mainly in MTT as players are more likely to AI as they try to get some chips and climb up positions. And as people bounces in and out the tables in an MTT, giving information wouldn't be a problem. Probably 10 minutes later you'll be in a different table against different people...