Sure, Why Not?: A Tongue-Mounted Toothbrush
This is the T2T (Tongue to Teeth -- not ATM) toothbrush. It slips on your tongue and then you lick your teeth with to clean them. It doesn't look like it would get between your teeth very well. The brush has toothpaste built in and was designed to be a disposable device to clean your teeth and freshen your breath while on the go and you can't use your hands (i.e. while driving or running from the cops). I'm not sure if you could also use the brush for sexual purposes, but my guess is you're gonna regret it. Privates and toothpaste don't mix, trust me. I had a good idea one time that turned out to be a very bad idea.
Thanks to Geoff, who told me I had something stuck between my teeth so I got up to go look before realizing there's no way he could see me. Man, you got me good!