We have a nail bitter in our family. My middle son, now ten years old, has been biting his nails for a while. His nails and finger tips always look clean, but it is because they are always in his mouth. We've tried explaining how unsanitary it it to always put your fingers in your mouth, we've tried badgering and bugging him every time he puts a finger up to chew on it, we've tried bribery with a banana split, we've tried just ignoring it. Nothing has really worked and the habit is as bad as ever.
I have hit on the perfect combination of motivation and nail polish.
First of all, he now wants to stop biting. Badly. There is a pair of fins for boggieboarding at stake. And he is just ready to get rid of the habit.
But this is not quite enough for him to quit. So I found Bite No More by SuperNail, which claims right on the package nothing less than 100% satisfaction to stop nail biting. It is a clear polish that is applied several times a day and tastes bad.
I showed him the polish and to my surprise he was completely willing to try it. So I painted his nails. Then we sat down to watch a movie, a time when he usually bites. Watching James Bond in an intense car chase, his hand rose to his mouth and his teeth came in contact with the nail. ACKK!! ICKK!! It tastes terrible!!
It worked! Every time he starts to bring his hand up, he remembers the terrible taste and stops himself.
I haven't quite gotten used to doing his nails several times a day. If I forget, he will remind me, "Mom! Do my nails!" It's a small price to pay for the nudge he needs to quit biting. Plus, his nails look nice and shiny, better than mine do.