There are almost as many canker sore remedies as there are people with canker sores! Well, not quite maybe but it can sometimes feel like that when you read all the options open to you.
It would take a whole website - and more - to list all the choices but here's a good selection for you to browse through. You're likely to find something here that will work well for you.
You can try dabbing salt on the sore - either directly with a finger tip or by using a Q Tip moisened and dipped into salt.
Others use a strong salt solution rinsed around their mouth and kept in contact with the mouth ulcer area for as long as possible.
If the problem is very severe then you might need to see a doctor or a dentist for a more medical approach to treatment. They are likely to use gels or pastes containing a steroid substance - or to prescribe some medications. A drug called colchicine is sometimes very effective for canker sores.
For a more natural approach you can make a mouth wash from clover leaves, clover seeds and salt - and then use this to rinse your mouth on a regular basis. This is a very traditional way of using local herbs and plants to heal mouth pain and canker sores.
Others recommend hydrogen peroxide, lysine or live probiotics as treatment and prevention options against canker sores and other mouth problems. You can read much more about these options elsewhere on this site.