Britishism or Generational Thing?

I've a quick question for you. I've noticed the phrase "go clean his teeth" in many HP fics, but I've never in my life said that I'm going to go "clean my teeth." I've always said that I'm going to go "brush my teeth."

Is this one of those British vs. American phrases, or this this a case of me showing my age (41)? Which do you do, brush your teeth or clean your teeth? And whichever you do, where do you live and how old are you?