Cleaning products such as Krud Kutter, Gutter Magic No. 9 and Gutter Brite quickly clean the outside of gutters, according to Gutter Helmet. Fantastik All-Purpose Cleaner is also effective against stubborn stains. Other gutter cleaners include Gutter Zap Cleaner and Streak Getter.
Many commercial gutter cleaners do not work well on mildew. However, these stains usually respond well to a solution of water, bleach, laundry detergent and trisodium phosphate.
In addition to a cleaning product, effective gutter cleaning requires appropriate tools. Soft brushes, rags and sponges clean gutter exteriors without scratching them or damaging the paint, which is particularly important for aluminum gutters. Thorough rinsing is also essential.