Okay, it doesn’t look the best, but I watched my OW instructor do this and it works better than any other method I’ve tried so far. Lick it! Yes, I said lick it. Just like spit, only more effective. Shove your mug right in there and lick every square inch of that mask. I’ve tried three different liquid defogs and this works better I swear. Only it looks a little gross to those on the other side of the window ;-)