This thread, for some unknown reason, just reminded me about a product Amway used to sell in the 60's & early 70's you'd spray on your tires for grip in the snow. I'm sure other companies had similar products. But it was amazing.
When I was a teenager my dad sold Amway and one winter after a pretty good storm we were driving down a 4 lane road in Roanoke, VA and saw a car not making it up a hill on a side road. So my dad, ever the opportunist, drove over and said to the person, "I have something I can spray on your tires that will get you up the hill. It's $5 a can, I'll spray some on for free, and if you think it's worth it, just stop at the top of the hill and my son will come up."
We sat there at the bottom of the hill for about an hour and sold two cases of it. Some people walked back down and bought several cans.
These were people with bias-ply summer tires and they all made it up without issue once the stuff was sprayed on the tires.
It was amazing stuff. They had to remove it from the market though because it seems it was also quite nasty.
I guess it was an early version of this
http://www.sportsimportsltd.com/lisptichgr.html