Homeowners should use a pressure washer detergent in their power washers, notes Pressure Washers Direct. These detergents are available in a concentrate that is added to water or a ready-to-use solution.
The cleanser used in a power washer is designed for use outdoors, so it should be environmentally friendly. These cleansers help remove stains on surfaces and kill off mold and mildew. Cleansers should never contain bleach as this base can damage the parts of the washer.
One example of a power washer cleaner is Simple Green House and Siding Cleaner. This concentrate that is first sprayed onto the surface with a low-pressure nozzle, and then rinsed with the high-pressure nozzle.