Gutter Klean is a house cleaner that removes black streaks from gutters, trailers and RVs. It may also be used as a degreaser. Do you have those ugly black streaks that just won’t come off of your gutters? We have the solution. Gutter Klean is a concentrated product, designed to aid in the removal of stains on Gutters. Simply apply product to gutters and rinse with water.