"Based on silicone" does not mean "degrades like silicone." It also doesn't mean your coating will behave like the silicone "in the scientific literature." If I toss a silicone spoon in the ocean, it won't be gone in a week. You can make plastic out of wood. That doesn't make it biodegradable. There are different kinds of silicone. Some degrade quickly, some don't. Some is toxic as it degrades. It can accumulate in fish like plastic, etc.
Without knowing how the coating wears off (in chunks when toilet is cleaned, etc), it's hard to compare. Also, if it's not actually silicone, we shouldn't be pretending it acts like it is.
Have any independent environmental assessment been done? What happens when you drink it? What happens when you feed it to fish?