Sasona gutters should be blown weekly using the leaf-blower. It's red and has a long attachment for ground blowing.
Twice or once yearly, the gutters should be power washed with a solution like below. (This is from the installer)
Here are the instructions for cleaning the gutters:
CARE & MAINTENANCE
Climatic conditions vary considerably from one locality to the next. In some locales, mildew and mold may be a problem. It appears as black spots or streaks, also known as Tiger Striping, occurring on the surface. For possible removal, prepare a solution as follows and clean according to procedures below: (AGI's warranties do not apply to Tiger Striping)
1/3 Cup Detergent (Tide for example) 2/3 Cup Trisodium Phosphate (Soilax for example) 1 Qt. 5% Sodium Hypochlorite (Clorox for example) 3 Qts. Water
CAUTION: GREATER CONCENTRATIONS MAY CAUSE DAMAGE TO YOUR PRODUCT
INSTRUCTIONS For surface soil or stains, resulting from industrial fallout, tree sap, insecticides, or chimney fumes, the use of ordinary non-abrasive household detergent is recommended. (For example 1/3 cup of Tide per gallon of water) The solution should be applied to the soiled surface by means of a soft rag, sponge, or soft bristle brush with a gentle rubbing action - do not rub vigorously so as to create glossy areas over the satin finish of your gutter or accessory products.
Soft bristle brushes equipped with long extension handles may be used to reach some of the higher areas. It is important that immediately following all washing operations, the entire surface be thoroughly rinsed with fresh water from a garden hose.
STUBBORN STAINS If stubborn stains are encountered, use a heavy duty cleaner such as "409" available in supermarkets or "Industro-Clean" available from local Amway Distributors. Heavy soil deposits may not be removable in one application and may require repeated cleaning over some length of time.
CAUTION: DO NOT USE CLEANSERS CONTAINING ABRASIVE PARTICLES SOLVENT OR AMMONIATED TYPE CLEANSERS OR PAINT REMOVER FOR CLEANING YOUR GUTTER OR ACCESSORY PRODUCTS. THESE MATERIALS MAY SOFTEN OR ACTUALLY REMOVE YOUR PRODUCT'S PAINT FINISH.