How To Clean Mouth Guard With Hydrogen Peroxide. After cleaning the night guard should be kept in its case and its lead should be intact. Then soak the night guard in hydrogen peroxide for at least 30 more minutes.
Do the same for the glass or bowl that you used. Let the mouth guard soak for at least a few minutes, then remove and rinse with water. If your mouth guard is discolored, try soaking.
You may brush the night guard with soap/water or just water.
Then, dip a clean toothbrush in warm water and scrub the dish soap into the mouth guard. Let the mouthguard sit in the hydrogen peroxide for 30 minutes. Then, dip a clean toothbrush in warm water and scrub the dish soap into the mouth guard. Thoroughly clean the appliance both inside and outside to lift away plaque residue.