How to keep a child from continually cussing?

[VIRGO]

I don't know if this will work for all children,but when my son started cussing around that age.I told him that when he cusses it makes his breath smell like poopy,because they are dirty words.He actually believed that if he cussed his breath would smell like dodo so he stopped cussing.He also get allowance for good behavior,and if he hears me or his dad say a naughty word,we have to put a quarter in his piggy bank.Sets a good example for him that we know cussing is bad also.