A dental mouthwash product, and method of use, comprising a water-soluble chlorite compound in a first solution, a hydrogen peroxide and a physiologically acceptable readily water-soluble oxidizing agent in a second solution, or optionally the oxidizing agent separate from the second solution as a powder, tablet, gel capsule, or liquid, wherein said oxidizing agent oxidizes chlorite to ClO2 within seconds, wherein the three ingredients are mixed to provide the mouthwash product. The mouthwash product may be used for any one or more of the following: as an antimicrobial agent for treating dental disease such as dental caries, plaque, gum disease, and / or bad breath, for strengthening gum and ligament attachments to the teeth, or for whitening teeth.