Ditto snomaes :)
I find the idea of brushing a dogs teeth,well....strange

Raw meaty bones act as my dogs tooth brush,i have never had tartar problems with any of my dogs,thanks to their diet which bones are a huge part of.
Chicken wings,pork/lamb ribs,knuckle bones etc. are all great for keeping their mouth healthy and teeth sparkling white :D
Goat do your dogs and yourself a favour and go to the butcher and stock up on some bones,they will love you for it :)