Not a dumb question at all...
CET is a producer of toothpaste for dogs.
The company is called Virbac.
They make a rinse if you cannot brush.
I think their site is cetdental.com.
You can get their products from entirelypets.com.
Vets sell CET but I have never used the rinse, so don't know if it works.
It should do something though.