How can you stop a dive mask from fogging up?

Just want to see what other tricks others doHow can you stop a dive mask from fogging up?
Step #1: Clean the inside surface of the mask. After manufacturing, there is a coating on the inside surface that needs to be removed. Use toothpaste (paste not gel) or a mild abbrasive (like Soft Scrub) to clean the inside surface. Don't just smear the toothpaste around on the lens. You really need to grind it in. Use some force.





Step #2: Using an anit-fogging agent (which is actaully very mild detergent) or spit, smear it on the inside of the mask. Dunk the mask a couple of times to rinse of the extra, and you should be good to go.





Step #3: If you completed both steps, and it fogs up again on a dive, I can pretty much bet you only smear the toothpaste around in the mask.





When student insist that they cleaned their mask ';with force'; and it still fogs, it must be my instructor magic that cleans that last time, because it doesn't fog once I clean it for them.How can you stop a dive mask from fogging up?
Doug's pretty well got it nailed, however I wouldn't use spit. Use the anti fog instead. The human mouth is one of the dirtiest places on the planet and contains an assortment of bacteria. You're opening yourself up to a possible eye infection.Anti fog works, is long lasting and dirt cheap.
I agree with what Doug says on the toothpaste. But just to add, I smear toothpaste on the lens even the night before I take a dive trip. Then just wash it before the actual dive. This always guarantees me a hassle free no fog dive.
Spit on it.





Its just as good as all the other methods, but you'll never forget where you left your spit or suddenly run out when you most need it!



I use a little dab of liquid soap on the inside and rub it around, mine never steam up after that.
spit ... anti-fog for windshields
spit in it and rub it around the glass