This reminds me of a friend that I had. He wanted to sell some scrap steel that his dad had laying around their farm so he called the scrap yard and asked them what the price of scrap was. They told him that dirty steel was one price and that he would get a higher price for clean steel. He loaded up the truck and headed to the car wash where he spent a few bucks washing all the steel that he had in the bed. Only he was disappointed when he dropped it off and they gave him the money for dirty steel. He couldn't believe it, he told them that he had washed it and gotten all the dirt off of it. He learned the difference between clean and dirty steel that day.