Summarize the following:
Use one part bleach to 10 parts water. Place the solution in a small bowl or denture cleaner container. Do not use bleach if you are allergic to any kind of bleach. Also, make sure to use gloves to protect your hands. The bleach kills the bacteria and plaque that have built up. Discard the solution after you've used it once. Be sure that all of the solution is gone. No bleach should remain to damage your mouth's soft tissues, such as your gums.

Summary:
Make a bleach solution. Soak your mouth guard for 5 to 10 minutes. Rinse after taking it out of the bleach solution.