There was a post a while back about different things people used to clean their racks, v-trays, bottom liner etc and someone, I don't remember who, said they used ZEP purple cleaner so I went and got some at Menards. I bought a gallon of purple industrial cleaner and degreaser, I mix it with water in a spray bottle and use it to clean my racks, etc. The stuff works like a miracle, I use an old meat tub and lay the pieces in the bottom and spray them with that stuff and it dissolves all the grease, smoke residue, etc. Unless something is REALLY burned on you don't even have to scrub, just spray and and let it soak for a few minutes, rinse off and done. I mix it about 25/75 cleaner to water. Even then you want to have some ventilation or be outside when you spray it, at least I do. It really keeps everything shining though. Just dont use it in the smoker itself.
