I hope "cat piss" is a trade name and not the real thing! Along the same lines, I'm using something called Zooke wax [check website], which isn't a spray but a semi-solid rub-on substance that works pretty well. The only real winter we have here is 3 months of inversion layers, and I'm blind as a bat, and I sweat like a pig, so anti-fog research is at the top of my list. It won't make the moisture disappear, but it won't form droplets either to blind you when facing oncoming headlights and such. Water just sheets up, somewhat blurry if the fog is thick but you can see through it, even with ice building up on my goretex. I used to use the packet wipes, but they're very limited and not nearly as effective as the wax. In a pinch, don't laugh at spit; its what scuba divers have used for years.