Last time I smoked something, I think it was a butt. The fat trap over flowed and since it was late at night, I said I'll deal with it in the morning. I cleaned up the hardened fat, sprayed it with bleach and cleaned it the best I could.

Today, probably a month or two later, I wanted to pressure clean the whole area. Look how nice and clean the fat area is. Maybe the trick to keeping dirt and mildew at bay on the bricks, is some liquid fat, let it set and then clean it with bleach. Maybe I'm onto something to keep bricks cleaner a lot longer.