Earlier quoted context omitted.
In a former flat I had a plumber over, we got to chat a bit. He said that in they often get called to subsidized housing, as the amount of water used in toilets there is often set to a low setting in order to save money. He was a bit more colorful, but in essence he said: With two liters of water you are not going to move 1kg feces far enough down the pipe, so it starts piling up. That's the reason why they get calle…
If you're only using the toilet twice per day, I suggest drinking more water :) https://www.healthline.com/health/how-often-should-you-pee But maybe you mean only flushing twice per day, despite using it more frequently, in order to save water? That would beg the question of how this coating material would hold up when subjected for hours per day to the "toilet environment" you produce vs. a clean water environment.
I learned that from a former colleague when I worked as a gardener