I use the Petz Life Product on Joey, it's comes in a spray of gel, and it's not that difficult to use. It softens tartar, and you have to brush it away with a toothbrush. It's said that if used early enough it prevents tartar from forming. I've been using for over a year now, and Joey at age two, shows no signs of tartar. Here's a link with more information, and some before and after pictures, it's pretty amazing.
PetzLife Products Inc - Products For a Healthier Pet