Yes, salt always. Put a big pinch of it and leave it on the sore, try not to swallow, just leave it in the spot on the sore. It numbs it and heals it. It has always worked for me.
Get some table salt (4 teaspoons) and dissolve it in water then wash your mouth out with the salty water. The reason the pretzel thing works is because of the salt.I recommend you Mouth ulcer home remedy through this you get instant of knowledge about how mouth ulcer relief .