Yes, pressure washing can remove deck paint. Before you apply a stain or paint to a wood surface, you need to make sure the surface is free and clear of dirt, dust, fibers, grease, mildew and moisture. When a surface is not clean, paints will have trouble sticking to the wood and stains will have a difficult time penetrating into the wood and this will likely cause premature peeling. Not only will forgoing this step cause painting to peel quicker, most of the unclean blemishes will show through your stain or varnish- thus resulting in a waste of your time and money!