I second that Abrevia (and for that matter, probably L-lysine) are for cold sores (viral, usually on the lips) whereas canker sores are much harder to treat (not viral but caused by foods, damage to the mouth, and other things, and usually inside the mouth on the tongue, cheeks, and soft palate areas.)
I have terrible problems with canker sores .... like ... they are pretty much constant, severe, and most of my life, actually to the point that I started investigating weird genetic disorders that might cause them.
Unfortunately, they are very hard to treat. I have tried every single treatment listed in this thread -- salt, milk of magnesium, alum, avoidance of various foods, you name it. Any benefits I've gotten from any of these treatments are so minimal as to possibly be a placebo effect.
The only thing I can recommend to you are over-the-counter remedies that contain some sort of substance that "coats" the sore. Cank-A is the one that comes to mind. It sort of puts a thin membrane over the sore and protects it for a little bit. It also has a pain releiver in it that works for a little while. It doesn't work great, but if you are very very careful, the coating will stay on for a while and help it feel better. If it is inside your lip (I think you said it was???), it will more likely stay in place for a while than on the tongue. It will probably make the pain bearable, but you'll have to reapply it a lot.
Honestly -- all the stuff with salt or alum or milk of magnesium or whatever that dries out the sore ... well, it does dry it out ... but it can also make it more painful. And in my experience, it doesn't make it go away any quicker. In fact, it can exacerbate the inflammation and make it a bit worse.
My two cents. Unfortunately, nobody knows jack squat about canker sores, and there's nothing out there that really works. Believe me, I've done the research....
