At one point, the company I worked for moved into larger quarters that had been hastily converted from an agricultural-products warehouse. There was a single bathroom in the building (as I said, hastily), and it was filthy. I expected this, due to the large amount of dirt that comes with this particular crop.
What I did not expect was the sign lying on the floor that said "Use the toilet, not the floor!!!" It was a cement floor, sloped toward a central drain, but still - ack!
I backed out of the room, went across the street to the hardware store, bought a bottle of bleach and some rubber gloves, and washed that room down with a vengeance. Walls were scrubbed (tile, thankfully) as high as I could reach; the fixtures were cleaned to within an inch of their lives; the floor was washed multiple times. I destroyed the cleaning rag and bleached spots into my sweatshirt, but it was worth it - I could use the bathroom without being completely squicked out.