As a dental hygienist and an ulcer sufferer - I can say warm salt water is awesome. alum powder will hurt but it's worth it. swigging with Jack Daniels or Listerine also burns but speeds up healing!, Go To to get more Gossip News!
Have not had a Canker Sore in years. But I remember getting them a lot as a kid during the summer after eating tomatoes strait out of the garden. Use to put Alum on them. Gone in a day or two. Careful as it smarts a lot and is very tart.