Just pinch off a chunk of this magical goo & press it repeatedly into your available dirty crack. (No, not that crack.) Press & lift, press & lift. You’ll see Tech Taffy eat up the crumbs & dust before your eyes. Place the chunk back in the container & tighten the lid after each use. When a full layer of Tech Taffy is discolored & full of lots of visible gunk, dispose of it & move on to the next layer.