With the new light in the bathroom, certain dingy spots were suddenly glaring at me. The sink had a calcium mark from a previous faucet. I tried CLR, I tried soft scrub. Finally I remembered the good old Brillo trick and got the calcium marks off pretty quick. I also got the soap stain off the sink.
I also scrubbed the bath with the brillo pad. Awesome!! It's my new magic eraser. Obviously not good for walls, but amazing on soap scum.