Many dogs do not want their noses messed with because those tissues are highly sensitive - touching IS painful even if they don't show it (dogs are stoic by nature). Dogs also have many nerve endings in their noses. Imagine chapped lips - ouch!
There are several ways of accomplishing this (depending on your dog). What we hear the most from our customers is to make sure your dog associates the application of Snout Soother as a "reward" - not as a negative or confining situation.
Holding down or confining may not be the best option, either, as most dogs will resist or fear constraint. If you coax your dog with a FIRM, but gentle, approach (and sometimes treats), you should get a better response.
You might try holding a food reward in your hand and let your dog get a sniff of it. As he is licking or nibbling the treat, try to carefully swipe a bit of Snout Soother on your dog's nose. If your dog begins to associate yummy treats with getting something put on his nose, you should have a better response.
You could also try tug toys or belly rubs - anything to distract your dog. Tug works well for many dogs and they will let you do just about anything to their noses with a tug toy firmly locked in their jaws. At that point, keeping the tug toy is way more important than worrying about anyone touching their nose.
Don't give up! They will finally end up with a healthy nose and be able to live pain free.