Plizzo anti-fog can be used for any type of glass to prevent fogging. Diving masks, swimming goggles, regular glasses, sunglasses, reading glasses, mirrors, etc. You don't have to apply it near the edge of the water, you can also do this at home. 1 or 2 drops of the anti-fog on the glass is enough, rub it in with a cotton pad and polish it until it is clear again. It stays on for several dives!

Clean the whole thing, including the mask box, with a silicone-free detergent and clean the glass extra with white toothpaste.