Surprised? Our #1 house-wash cleaner is great for removing gutter streaks. At a concentration of about 4:1, PowerHouse erased streaks without any problem. Apply it with a rag or brush to a dry gutter and wipe the tiger stripes right off the surface. Then rinse. A faster, easier way? Sure! Shoot the dry gutter with your PowerHouse mix using an X-Jet and then immediately rinse the gutter with the same X-Jet. With practice, you can get great results on a 40' length of gutter in about three minutes flat.