I have tried TONS, tons of medications in hope to cure canker sores, the only thing that actually worked for me is from a Chinese herbal store in Toronto, beside 风华 grocery store on Warden. It's a dark powder, smells like 西瓜霜.
Nothing else worked for me. There are ways to ease the pain, like salty water rinse 4 times a day, or hydrogen peroxide swab 3-5 times daily, there are also topicals that are available in local drug stores. I had my dentist prescribe a local anesthetics for me, I'll get the name for you tonight.