I get these all the time, usually in a series (once I get one, then as soon as it fades away I will get another in a different area of the mouth). They are annoying as HELL, though my treatment has always been to leave 'em be... takes 5-7 days for them to go away, occasionally longer. (I tried the benzocaine stuff a few times, never liked it.)
Now, as for the SALT remedy... WTF? Are you guys insane? The very idea of pouring salt on those buggers makes my eyes roll... *shudder*. But if it really does work, well hey... maybe I should try it.
I really hate canker sores, especially when I want to give a good blow job but just can't because of the pain.
Seriously though, it has happened! Kissing has been painful too, with some of my recent ones...
So a little salting may be in order, if you all SWEAR that it is worth it!!