Follow Basic Steps 1,2,3,4. If stain remains, mix 1/2 cup white vinegar with 1 cup warm water. Use a clean, white terry cloth towel to blot vinegar mixture onto stain. Blot with clean, dry, white towel, often. Repeat as necessary.
Rust can be tricky- it requires an acid to remove, and depending on the type of metal that caused the rust, this acid can change. Most rust is removed very simply with a rust remover (oxalic acid). Do not use hard water stain and rust removers, as this can permanantly discolor your carpet. If you can find oxalic acid, use a very mild solution and blot until the stain is gone.
If stain remains, call Zerorez® to set up a professional stain removal consultation.