Composting toilets are not new, of course; I remember them in the 1960's.
The names changes from time to time; back then they were (in my experience) called earth closets although that term is now reserved for something else. A little, moveable shed; inside was a box bench with a suitably sized opening over a hole in the ground. A pile of loose dry material (earth) and a little shovel to spread it over the solid matter. The wee must have drained away and, eventually the composited material removed or the shed relocated.