Canker sores are more of a nuisance than a threat, but almost always a sign of impending illness. I only get them when I am coming down with something. I’ve always poured a little salt on to make them go away. I’ve found that works pretty well! The suggestion below is to use alum powder. Is this the same as baking soda? I’m not sure, but there is a warning to NOT swallow the alum, so I’d rather use salt safely and not worry about it.
Read the theory behind this remedy in the link below and decide for yourself if you’ll try it.