Excellent - thank you, Brooks! Tanker is 11 years old and is just now having dental issues, poor thing. I didn't even know until I noticed his breath was getting bad! I had his blood work done when he went in for the cleaning and other than that, he's very healthy. Having his coat brushed and canned tuna are his two favorite things in the world, so I'll use those as rewards.
I'll check out that fragaria 6C, it looks easy enough to get. My vet did recommend some kind of enzymatic rinse in addition to brushing.