On a concrete floor I use dirt. Spread dry dirt (the finer the better) over the resin and let it soak up the resin. Use a thin blade putty knife (I use a sheet rockers knife) to scrape up the goo, repeat as needed. This will clean the floor to the point of being nonsticky. It will however leave a dark spot because some of the resin has soaked into the concrete.
Jerry siegel