I use the one from Natures Farmacy (yes it's spelled like that!). It last me a long time even with daily use. It comes in a powder and even my picky dog likes it. I pick it up at dog shows but you can also order online.
Alex, did you find a vet in the Bay Area (or somewhere in the South Bay) who specializes in dental work for B's?
Pat (Tanza), do you know any vet near the South Bay who specializes in dental work for B's?
My B has a cracked tooth/molar which I found and took a photo, showed it to my vet and he suggested tooth extraction. Since he missed it during the physical last week and he hasn't even suggested an x-ray or something to confirm if extraction is the only option (he seems to just base it on the photo and nothing else), I'm suspicious and would like a second opinion from another vet. (I did ask for blood work and the vet said the results are fine, no issues.)
I wish the state would also accept titers for rabies, but maybe in the future they will.
There is an in-house titer kit available from Synbiotics in San Diego called "TiterChek" that vets can do at their office to check for adequate antibody levels on a pass/fail basis – it won't give you a specific antibody count the way a titer sent to a lab will, but it will let you know if your animal has enough to protect them. We have those done whenever we need to board our dogs rather than having boosters.