[codefox1]

Well ,from memory, you can still cheaply get a can of LYE (AKA Sodium Hydroxide) and carefully dissolve in a couple of gallons of cold water outdoors with eye protection and of course heavy duty gloves and I believe a stone or galvanized tub will do. Add a few ounces of cornstarch dissolved in hot water to make the stuff into paste. Stuff is not so nice to water sensitive thin veneer, Antedote is of course White Vinegar, but a good flush with water also works. Runoff should be directed towards driveway and street whereupon it does no further harm that I am aware of.