Try a magic eraser. I should own stock in those. They are the only way I can survive having white counters.
Agree with Amanda...Magic erasers are great!
try Bar Keepers Friend. My water has a lot of iron in it and it removed the rust stains that causes. Good luck.
Snobol toilet bowl cleaner and then clean again with soap and water!
CLR--a calcium, lime, & rust remover. Be careful with bartender's friend or any abrasive product that might scratch.
I use a product called Whink rust remover. It is very much like CLR but concentrates specifically on rust. I find it at Menards hardware store.
Next on the list after you get the rust stain out is to properly season your cast iron...so this will not happen again in the future.
Check out this article I wrote on Seasoning cast iron cookware.
I'd try a "magic eraser" before I tried any abrasive.
Thank you for all the helpful advice!
try to find "bar keepers friend" the stuff is great - I had rust stains on my tub that I thought would never come out and they are gone!
Debbi beat me to the Barkeeper's Friend recommendation. It removes everything without scratching glass, tile, or plastic. Another product that works well for rust removal is CLR, the old tried and true...