I'm wondering if there is any sort of coating I can apply to my walkways that would melt the snow or ice... like a calcium chloride-based coating or something similar. Do those exist? I suppose I could always run a heat coil under my sidewalk.
heating coil goes in the sidewalk when you pour. If you're serious about this you need to look at a recirculating liquid system that is heated. Electric coils will cost you more than the electric bill for the entire house.