Customers expectations are way to high when asking you to quote for decking cleaning. Years of neglect, sundried, slimy, flaking...absolute nightmare and dangerously fragile. I always express concern at the neglect and state of the decking and tell the customer politely that I don't offer a rejuvenation service. However, if the conversation starts off with the customer saying "I cleaned it myself last summer, it only took half an hour with my Karcher" I quickly lose interest.