If your dog got sprayed by a skunk in the mouth how do you make him stop smelling?

If your pet gets sprayed by a skunk, wash him with Dawn dish detergent. Just as Dawn cuts grease on dirty dishes, it will cut the oil in the skunk spray. I would ask your vet about treating the mouth.

Seriously, according to Mythbusters, a baking soda bath works better than tomato juice.

Easy tomato-juice bath, then I take my dog to a regular bath.

If you want your dog to smell like tomato juice and skunk spray, give it a tomato juice bath. If you want to get rid of the skunk smell quick, mix 1 quart hydrogen peroxide with a quarter cup of baking soda and a squirt of dog shampoo in a plastic bucket. Add a cup of water and mix thoroughly. Put on some rubber gloves and get the dog in the grass and apply mixture with sponge or wash rag. Let it sit for 15 minutes and give it a regular bath. The odor will be neutralized and you won't have a pink dog. I have 2 labs and live in the country and they get hit at list twice a year. This works. Don't premix the hydrogen peroxide and baking soda and store in the cabinet as the solution is highly unstable; e.g. kaboom....

I tried peroxide, tomato juice and baking soda. All it does is spreads the skunk oil and the smell. Dog shampoos masks the odor temporarily. Veterinarians use Doggicleen Skunk Spray. It works!