Muzzle is my protocol for my aggressive dog. Though my vet really doesn't want to vet my dog either. Especially a procedure that takes some time. Xanax for vet visit is an option, but I've heard you should give it for awhile before just giving a dose for a vet visit. Valium may be more effective, not having to be built up in the system.
I've aced my dog for vetting, but it completely frustrates her and she gets more aggressive because her mind is not calm, and her body won't do what her mind wants. I'd rather have a calm mind and body.
That said, I use Zymox for my dogs ear issues, it is effective for yeast and bacteria, once a day treatment for 10 days.
This is the size I get, because my dog has environmental allergies/ ears are always getting gunky: Zymox Otic with Hydrocortisone (1.0%) - Clinic Size (8oz)