Tung Gel. The major cause of bad breath is bacteria that sits on the tongue. 90 percent of bad breath is caused by sulphur gases that are released as bacteria digest protein in your mouth. They need to be removed as quickly as possible. The surface of the tongue is irregular and there are plenty of crevices where these bacteria can hide. The TungBrush and TungGel are specifically designed to get into these grooves and clean them thoroughly. Action...Loosens sticky plaque from the tongue. Zinc neutralises bad breath. Works better than standard toothpaste. Great-tasting formula leaves tongue feeling fresh.