Washing the floor ahead of time would be time wasted. In this case, dirt is your friend, as the dirt provides a layer of lubricant between the shoes and the floor. Think of the floor as a strip of adhesive tape. Sprinkling dust on the tape reduces the tackiness to other objects. So that is what you should not do. What should you do? I would recommend that you tell people to spread the word that the floor is tacky and to select appropriate footwear. In this case, I would go with worn leather/suede or a bowling shoe. In a pinch, people can just use socks. Here is an FAQ on dance floors, but I don't recommend putting any substance on the floor: http://www.eijkhout.net/rad/dance_offnet/floor3.html Good luck!