Canker sores are a pain in the mouth! There is no known cure for them but many treatments to help heal them. If you mix some salt, best to use Epsom salt, with water & rinse your mouth several times a day will help the ease the pain & start healing. Ointment’s you can find at your local drug store also helps especially if you use the ointments as soon as you feel the canker sore starting. Gargle & apply ointment it will soon go away.