One thing that always interested me was the concept of a homestead “methane digester”. Thus would allow a standard flush toilet to be used, to feed a digester, as well as barnyard waste/soiled bedding... to produce methane to be used for either cooking or possible light power generation. It would also produce compost for gardening. I’ve seen third world village based examples of this. Very low tech and easy to build if you know what you are doing.

Win-win-win

Sewage treatment, low input cooking fuel, garden fertilizer