I work at a school for boys. NO SWEARING ALLOWED! When they do I make them write the same sentence 10 or 15 times, relpacing the offensive word or phrase. They are incredibly creative. Often they surprise me, my favorite is , " Oh, cussword, cussword, cussword!" It gets the point across without using the offensive language. 
We often have the air filled with, " What the diddly hoorah..?" , " Have you lost your tiny mind?" and the ever popular, " How in the bogslime..?"
Depending on your audience, this exercise might help. Good Luck. 
BJ