Stainless steel mug – Use oil to the mug. Apply the mineral oil for rust stains on the mug with a paper towel. Wait 15 minutes for the oil to penetrate the rust. Then scrub the rust with a wet scrubbing pad. Wash crimped in soap and water and dry with paper or cloth. Scrubbing too hard can damage the stainless steel surface which is why oil is applied first.
Search white vinegar for stubborn stains. Buy white vinegar and pour some into a paper towel. Apply vinegar to the rust stains on the mug. Wait 15 minutes to 30 minutes for the vinegar to work on rust. Then gently scrub the rust stains with a damp scrubbing pad. Wash stainless steel mug with soap and wait and bland. The ascetic acid in ethyl helps remove rust and is a non-toxic household cleaner.
Use Citrisurf 77 Plus. Buy Citrisurf 77 Plus online or from a home improvement store, recommend The Rust Store Citrisurf 77 Plus in his article “Removing Rust on Kitchen stainless steel.” Put a little rust remover on the stainless steel mug and wait 30 minutes. Then wash the rust remover with water. According to The Rust Store, “Not only will this product to remove rust, but it will help to keep it from rusting in the future.”