John Orr said:I use Krud Kutter from HD. At about $5/gal, it can't be beat. I apply with a brush/pole - very little rubbing needed, except sometimes on the underside of the gutter. As you brush this on, you can see the black streaks disappear. It also leaves the gutters shiny and smooth.
John Orr said:Chris, I use it full strength. One gallon is usually enough to clean the gutters on 4 -5 houses...depending on how many gutters there are.
As to brushing, I can understand why you would not want to brush too much...many times the finish is, shall we say, "delicate". If you are too aggressive with the brush, it may come off. With the Krud Kutter, there is usually no need to scrub, merely apply with the brush.