A DIY toothpaste: hydrogen peroxide 3% (topical solution) and baking soda.
Add a few drops of hydrogen peroxide to plain baking soda to form a paste.
Hydrogen peroxide is commonly used as a “debriding” mouthwash (when mixed with water) to help remove natural secretions that can aggravate a sore mouth. It’s also considered to be a homespun method for whitening teeth. In any application, hydrogen peroxide should not be ingested.