It is true that LeafGuard installers nor the company says the owner has to keep the black *** from accumulating on the lip. It took me a couple of years to figure that out and I simply take the cheap toilet brush and attach it to a 10 foot plastic pipe and brush the lip. It takes a little time but brings the gutters back to as new performance. It is a shame the company has not listened to their customers and offered suggestions. At least the customer still has both feet on the ground. Be prepared to B User's recommendation: Be prepared to inspect and clean the lip of the gutters.