Apologies if this has been mentioned recently (nothing came up in search). My bath was badly scratched on the side from my gold bracelets which I never remove. It was so bad I was thinking about having to buy a new one. A friend suggested I try some neat bicarb of soda on a just damp cloth using a circular motion. I just wish I had taken before and after photos! My bath looks like new; I am so chuffed that I wanted to share.
My rings caught on the doors under the handles and again, the bicarb worked wonders.