Ah! Okay, part of the issue I was having was not understanding that the % clean was measuring the entire screen, not just *the room interior*. As evidenced by this rogue pixel, hah. Okay, problem solved. (However, since you have lightswitches already, perhaps consider a blacklight tool?)
I saw the empty open chests, maybe just having "decor" chests be openable but empty?
And I just found an infinite water source outside the first room. Does indeed look different! My first playthrough I simply opened *all the wrong doors*, haha.
Again, excellent game. Great job on this one.