1) Put five or six drops of grapefruit seed extract in a glass of water, using as a mouthwash once daily.

2) Hold a wet tea bag on the sore. The acid in the tea acts as an astringent, relieving pain and promoting healing.

3) Apply baking soda to sore several times daily. It reduces amount of bacteria in the mouth for faster recovery.

4) One drop of licorice root extract on canker sores every hour can reduce pain and speed healing. That's because the remedy is rich in tannins, which are potent anti-inflammatories.