Can you tell me if hydrogen peroxide is suited for children over 6 years old as mouthwash?

MW taste: It will not harm however you may want to try a mw that taste better. Why do you want to use a mw on someone so young? Proper brushing monitored by the parent should prevent bad breath.

No: H2o2 or hydrogen peroxide is a potent oxidant and only has very limited oral applications. For kids, use a non-alcohol mouthwash possibly with Fluoride depending on other Fluoride sources where you live. Save the peroxide for cleaning dirty wounds away from your mouth.

No: Straight hydrogen peroxide should never be used as a mouthwash at any age. Commercially available products with hydrogen peroxide contain very small amounts. You can do a lot of damage to your oral tissues if used as a mouthwash.