Or you could end up like this Romanian teenager:
When questioned further she admitted she and some friends had been watching a pornographic movie and that she had swallowed the brush afterwards while practicing the technique for oral sex and imitating the women in the film.
A spokesman for the county hospital in Suceava where she was treated said: ‘This girl is very lucky. She did not suffer any internal damage because of the toothbrush, but things could have been much worse for her.’
Besides everyone knows you’re supposed to practice using a carrot or, if your boyfriend is particularly impressive, a cucumber.
At least she has gone where no form of dental hygiene has gone before. The back of her mouth is probably the cleanest in the world.