We had a fire on our deck two weeks ago. It didn't affect my neighbors' decks or homes, but the one neighbor said her siding is dirty from soot from the fire. We looked and it seemed fine. Hubby is nevertheless power washing it for her. I told hubby that it was like during my hospitalization for ECT when my roommate ordered me to clean the shower stall of my "ECT hair gel", which was a figment of her imagination. I superficially "cleaned" it just because I was not in a state to be having a fight with a bully.