Well, much to my suprise, my son used a completely diffefrent approach with his two 5 year olds. The first time I heard my grandson call his dad a "poopy (other word) head" I almost fainted. My son just sat there, "yeah... that's right, daddy is a ****head"... and went on about his business.
I called him out on it immediately, and he told me. That in his day care, all the kids were getting in so much trouble for cussing he decided to try something and it worked. He told Luke to pick a word, any cuss word, and that he could use that one at home and in private, but he could NEVER use any other word outside of that. He didn't know one word from the other, and he picked this one. And he NEVER, EVER cusses at any time, at school or at home.
That was two years ago, and now, he is so used to being able to say it... he doesn't. He doesn't care, he has found other words, that he thinks is just as cool, that are not cussing to use, and it ws never a big deal in their house.
I don't know that I would reccommend that, but his son didn't cuss behind his back and didn't get into trouble at school when other kids were. So... go figure. KWIM?"