A method for stripping a floor using a concentrate prepared by mixing a substantially nonchlorinated concentrate containing a floor finish solvent and an at least partially unactivated water thickener. The concentrate is diluted merely with water at an intended use location to activate the water thickener and noticeably increase within ten minutes or less the viscosity of the resulting mixture, then applied to a hardened floor finish atop a floor and allowed to soften or dissolve the floor finish so that the finish may be removed from the floor.