Technical Rust-paint cleaning question.

What's the best way to clean rust stains on paint? I noticed my stored car has had rusty water dripping on it! The local car wash generously offered to clay it for only ten zillion bucks! It's not severe.
Best way to go?
Clean with citrus cleaner? I have 6000 8000 grit paper. Should I spring for a clay bar? Paint is Ford Grabber Blue clearcoated.Anybody?

 

Clay bars are cheap,labor is expensive,try it yourself. HRP

 

Uh..I am doing it myself. Thought maybe somebody had some good advice.

 

Use oxalic acid. It removes rust. A product called Barkeeper's Friend has it. Available in your local grocery store.