My wife and I managed to drip candle wax all over a stone floor and the nearby carpet a couple of New Years Eves ago. A friend, who is a professional carpet guy, told us to lay a brown paper grocery bag over the drips, and then run a warm iron over the paper. The iron doesn't need to be very hot for the wax to melt, and capillary action sucks it right into the paper fibers. Sounded bogus to me, but it worked perfectly, absolutely perfectly. I'm guessing that the temp would be low enough to leave your deck intact, too.