I spoke to the dentist, because I can't get DS to brush his teeth, but he will walk around with the toothbrush in his mouth, moving it around, playing with it and she said that was okay - because it was better than nothing.

I have no luck with teethbrushing, but sometimes I can get him to brush his teeth when he sees me brush my teeth, and other times, DH can get him to brush his teeth by sticking the toothbrush in his mouth, pretending to brush his teeth, then saying "Your turn" (if that makes sense)

Good luck.