I do Lily's teeth every day because she has a history of very serious dental problems. If that weren't the case, maybe just several times a week would be okay. But here's my thinking - if your dog will allow you to do it without having to call in the Marines for support :lol: then why not do it every day just to be sure.
A dry food also helps and there are lots of "dental chews" available (not rawhide, as has been pointed out already). Princess Lily is fussy and won't eat any of the chews (good thing I have a friend whose dog gladly accepts handouts of opened bags of chews and treats). :lol:
You're asking the right questions and you are definitely in the right place for answers.
A rawhide is not going to do too much in terms of breaking tartar off the teeth, actually dry food will do a better job of this. Nylabones, hard dental chews, and CET chews with enzymes are great for this purpose, but I would combine it with brushing as often as you and your dog can tolerate it. The mouth is oddly enough the number 1 entry route for bacterial infections into the body that can cause liver and kidney disease as well as heart murmur and overall sepsis. Keeping your dog's teeth clean and healthy will definately extend its life! I mailed out a bunch of dental kits to chi-people a few weeks ago, did you guys get them? I'm all out now, if you want one, I'll let you guys know when more are available.