Let the customer know you are not depending on pressure to clean the soffit s and gutter facing. Youbare using your pressure washer for rinsing purposes. As far as the gutter facing is concerned, I use a degreaser called Tough on grease to get the black shingle run-off. You may have to use a little elbow greaseby scrubbing with a soft brush and rinse. Don't let what you scrubbed dry or you will have to spray, scrub and rinse agin. I get it from my local Janitorial supplier. I believe it's made by Spartan. Other degresers probably work well. Find one and stick with it.