I've been letting him have the
Purina Dental Chews -- it says they're a "veterinary diet" but I don't know, I got them on chewy.com w/ no RX. He likes them and they are VOHC approved so maybe they actually clean his teeth a little bit too in the process.
He gets the occasional bully stick when I feel like paying for them. The chews do come in handy for boring or rainy days so he doesn't drive me too crazy.