Rust can slowly eat away at metal items, making them unattractive and weak, but you can restore them by eliminating rust with salt, which acts as an effective mineral abrasive.
Mix salt and enough lemon juice or vinegar to make a thick paste. Apply it directly to the rusty area, ensuring it is nicely covered, and then start scrubbing away the rust.
Alternatively, mix the vinegar and lemon juice together and then sprinkle the area with coarse salt. Scrub the rust and then rinse off any salt residue.