Willy,
We too have used our battery operated tooth brush on our ferrets.
Discovered it by accident when my husband was brushing his teeth in the
ferret/ bath room and the sound drove them crazy.  I bought a few on sale
and they seem to like it --the sound/movement seems to distract them from
what you are doing.  Only trouble is make sure you dont mix up the
toothbrushes and use the ferret brush in your mouth!!  haha
 
Rita B.
[Posted in FML issue 4706]