TSP LIQUID SUBSTITUTEior and exterior surfaces. Phosphate-free concentrated cleaner - one quart makes up to 4 gallons, and one gallon will make up to 16 gallons of cleaning solution and requires no rinsing. Recommended for walls, woodwork, ceilings, concrete, metal, vinyl and aluminum siding. Removes mildew stains when mixed with bleach. Can be applied by hand or with a pressure washer.