Sherwin Williams says
A: Maintenance cleaning is vital to the overall service life of a painted surface. However, when selecting a cleaner, be sure to use a non-abrasive cleaner. If cleaning a waterborne paint, avoid products that are ammoniated. Mild, soapy water will generally suffice. However, always test the cleaning solution in an inconspicuous area to ensure that it does not damage the paint film.
Mild liquid dishwashing soap With a soft brush
(Dawn®, Ivory®, or Joy® )
and water. (Do not use any
harsh cleaning chemicals)