Sorry, Sweetie...I go back to my first post: use TEA TREE OIL!
Because HELLO: it kills viruses. bacteria. goofies. doofies. Gargle with it and put it directly on the sores as they begin to devlop. Put it on your tooth brush to kill the goofy/doofies that live there. Change your tooth brush every 6 weeks.
By the way, canker sores are Herpes...