Has anyone ever heard of or used "Propellant 49". I just found it on a website and it states that it is #1 on the market and can melt snow 12 times faster than calcuim chloride and stays working up to 36 hours after it is applied. It also states that it is the most environmentally friendly on the market. They sell it by the drums instead of the bag and gaurentee the storage of it up to 2 years and it will still be just as effective. Just curios?