In my locale, take-out pizza is usually provided directly on the interior surface of the pizza box, and so any grease spilling between slices or over the sides (garlic butter sauce on the crust dripping over the edge of the crust, for example) lands directly on the box.
Usually my pizza comes on wax paper or the like, and the box is either grease free or close enough (like a tiny spot or two).
Or it’s frozen/refrigerated, and wrapped on plastic, so, again, the box goes in recycle.
I don’t put soiled things in recycle, but you can’t tell, cause it rains often and everything end up looking fucked.
In my locale, take-out pizza is usually provided directly on the interior surface of the pizza box, and so any grease spilling between slices or over the sides (garlic butter sauce on the crust dripping over the edge of the crust, for example) lands directly on the box.