What Makes You Fizz?

Ever put hydrogen peroxide on a cut and it foams and fizzes? Or have you ever garglyed with it and it makes you look like a rabid dog foaming at the mouth? My husband and I have an ongoing debate...I swear that the hydrogen peroxide foams and fizzes whenever it comes into contact with or is killing bacteria. My husband thinks that is an old wives tale and that it foams or doesn't depending on the depth of the cut...what does everyone else think? Anyone know the answer?