Unfortunately, a Himalayan chew stick is way beyond Thor's abilities. Sometimes I will give him the rinds of a hard cheese after I've finished with the cheese part, he likes those a lot. I even asked the local cheese shop if I could have the leftover rinds, but they were like, ew, no, we throw those out. They do love Thor tho.
I do brush Thor's teeth, but even with that, it's like there's new plaque every day. It's a hopeless battle. I don't get his anal glands expressed anymore, and he seems to be fine there.