Cheese rinds bring fat along, and fat stays liquid only while it is warm. Two stages grind it fine enough not to settle in the bend of the trap. Natural rinds, like those of Parmesan-type cheese, are hard: in small pieces they are fine from the two-stage models up. Rinds with wax, paraffin or plastic, never. Never rinds with wax, plastic or labels. With that one precaution it becomes an ordinary scrap. If you produce a lot of it, it is worth checking your water utility’s rules.