And are enjoying using it..correctly. Oops. I'd be pretty embarrassed if they said it at school in a few weeks (we are new to the school), so I'm trying to distract them by using silly exclamations (phooey! Fiddlesticks!) as often as possible in hopes that something else catches their fancy and sticks in place of this one.

Any good ones for me to try? Can be real or made up, the goofier the better. Bonus points if it's something they don't know and I could convince them it is a "bad word".