Makani has been teething hard core too.
I would take a clean, baby, wash rag, wet it and stick it in the freezer. Then I allow him to chew on it with supervision. The rag is pliable enough that he can manipulate it into his mouth and get a good chew going on.
He has the teething rings and teething mesh pop thingies too, but with his CP he lacks the motor skills to really get those into proper chewing position. So for him the rags work great! I keep a few in the fridge at all times and rotate them out.
I have also purchased those Gerber teeting biscuits. They're hard as a rock so he can really chaw on them and they sort of melt, they're really messy though, because cookies don't exactly 'melt' they more like turn to mush.
Anyway, I still only will allow him to have them with supervision, As anything is a potential choke hazard and I don't like to trust the package labels when they claim they're totally safe.
I wouldn't put any drug on the gums. Some drugs break down tissue, such as your gums. And a lot of drugs can cause tooth decay. I am very leary about using any drug on my baby unless the pediatrician prescribed it.
Over the counter products aren't all that reliable with their dosage. (As seen with the whole baby decongestant recall)
Even tylenol can be dangerous.
The dosage should go by weight, And all babies weight varies. So I would assume that there isn't a safe recommended dosage that can be arbitrarily slapped upon a label and go with what the Doc says. Sadly, the drug companies care more about making a buck than they do about whether or not their recommended dosage is in fact safe and accurate.