This is reported to be a safe way to kill all the bacteria in your mouth. It is reported to be effective against dental hygienists, halitosis, or root canals. It may also whiten your teeth. Your dentist and dental hygienist may not approve.
"patients may use a diluted solution of sodium hypochlorite (bleach) (0.1% (1000 ppm available chlorine) or less dependent upon the patient's taste tolerance),
This is about 1 teaspoon of bleach in 200ml of water.
Here is the reference:
Slots J: Primer for antimicrobial periodontal therapy. J Periodont Res 2000; 35: 108: 14