I do it, but not as often as I should. I should brush their teeth 2 or 3 times a week but I only do it maybe once a week. Right now I use a toothbrush and Nylabone tartar control pet toothpaste. Also, I just bought tooth and gum wipes.
It's not an easy thing to do, I just make sure they get something extra special for a treat after the brushing.