I have a prospect who just built a house with stucco on exterior. Not having gutters and having built the house on red clay, the clay has splashed up and sat on the stucco near the bottom of his house for awhile. Someone came over with a beginners' pressure washer and tried to pressure wash it off. Unsuccesful at that, he tried simple green, still no luck. I am really not sure what will remove the clay stains. Any ideas would be helpful..thanks Bob G.