Baking Soda can neutralize acids and reduce inflammation. It can be used in various ways. Though less painful than salt, using baking soda still hurts. Below are the most popular methods, listed from the least to the most painful.

Mouth rinse

Mix some baking soda and water in a cup, then swish in your mouth for about a minute.

Applying directly

Apply a pinch of baking soda (or make a paste by adding a few drops of water) directly to the canker sore. Try to keep the baking soda in place for at least 30 seconds.

Scrubbing

Some people have reported that scrubbing a canker sore with baking soda until the white layer disappears helps it heal faster.