We used ammo cans for 16 days on a Grand Canyon / Colorado River rafting trip. It's affectionately named a "groover" from the time before someone thought of putting a toilet seat on it. Since it's a "leave no trace" National Park, you pack everything out. After 120 degrees for days on end the "burping" isn't pretty...
Down Under Outback ..humour ....
Thunderbox is far more polite than "The Crapper"
or The Dunny .... as we usually call it
and there is actually a town in the outback called , Dunnidoo .... hahaha
I always loved that name. When I was a lad, 40 or so years ago, we called the pit toilets at Voyageur National Park campsites "thunderboxes". They are basically an outhouse without the house, just a wood box with a toilet seat on it over the pit.
Mosquitos could be problematic whilst you were sitting there...