Not always. You would only muck in the winning hand if you knew your opponent was going to bet big on his hand so that you could get the must money. SO you would wait for him to call or raise the final time to muck in your cards. If you do it before that and he folds, you will have to throw in the good cards you worked hard to steal out and muck in, and not get much money for them. But you could still use the misdirection of everyone focusing on him when he is putting his chips into to call/raise once he has decided to do the muck as the cards are revealed. There are other mucks that happen as the cards are turned face up. There is one or two in Steve Forte's GPS, and also one was shown by R. Paul Wilson in the Real Hustle Show, which was a standard muck adapted to turn the two cards face up in the same motion. Although I don't know where this muck could be learned.