We use OraVet but the first application has to be done under anesthesia when the teeth can be dried off I think.
I can't tell you if it really works because I started brushing Ellie's teeth at the same time as starting the OraVet, however, I will not stop using it because Ellie is doing so well. She has stage 3-4 periodontal disease and her teeth are great now.
Some people may say don't use it and your vet just wants money but really, that may not be the case. It is very safe and worth a try in my opinion.
The only thing is, you are instructed to use 1 container per week. Since Yorkies have such small mouths, don't let anyone talk you into that one.
You can get by with 1/2 container.
I have even thought about splitting them into 1/3 but don't want to reduce the amount too much, so we will see.
Synovi G3 is fine. If you aren't happy with it, a lot of us use Cosequin.