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.