Buckminster Fuller was a 20th century inventor and visionary who did not limited to one field of expertise. He worked as a ‘comprehensive anticipatory design scientist’ to solve global problems. And one of the problems he chose to work on was the toilet.
He devised a four, stamped sheet metal or plastic commode that was light enough to be carried by two workers. They’ll fit up tight staircases and through narrow doors, allowing retrofitting in existing structures. All the appliances, pipes, and wires are built-in, limiting on-site construction to simple instillation hook-up.
With this configuration the interior has no germ-harboring nooks, crannies, or grout cracks.
This focus on sanitation was part of a larger effort known as the Dymaxion House which was meant to use a minimum of materials to provide maximum living space.