What's the best way to clean a porta potty after a long-term rental?

A light wipe down with mild dish soap and water is all it needs, since the operator washes and sanitizes every unit back at their yard after pickup anyway. We did the same thing after our community garden rental and the driver basically said thanks, but you didn't have to.

Sweep or wipe the loose dirt off the floor, pull out any trash that got tossed in, and wipe the seat and lid with a damp rag. Done.

What I'd skip: bleach, ammonia cleaners, and drain type products. Anything you spray or rinse around the seat ends up in the holding tank, and the blue tank chemical is there to break down waste and keep the smell down. Harsh household stuff can work against it, and bleach plus ammonia makes fumes you really don't want in a small closed box. Also don't hose it out. Extra water just fills the tank and sloshes around on the truck ride.

Two things that actually help on pickup day: keep the door and the gravel pad clear so the truck can back right up, and tell them about anything broken, like a latch or the paper holder. They'd rather hear it from you than find it later.

For a standard unit that only saw weekend use from 15 people, you're in good shape.