Brushed nickel is a brushed textured nickel finish on a surface. Many companies use brushed nickel on products, especially in home fixtures. Rust commonly forms on brushed nickel kitchen or bathroom fixtures such as faucets, drain tops and showerheads. Typically, this "rust" consists of not only rust, but also other minerals such as limestone as well as chemicals from your water. As harsh cleaning methods can damage brushed nickel, removal of this rust requires that you dislodge it with a mild cleanser and light scrubbing and/or dissolve it with a mild acid.
Rub a mild cleanser, such as a mild multipurpose household cleaner or mild kitchen or bathroom cleaner, onto the surface with a lint-free microfiber cloth. If you're dealing with encrusted mineral deposits, brush the area gently with a soft-bristled toothbrush to dislodge the deposits. Rinse the area thoroughly to remove all residues and then dry completely with a cloth.
Mix one part vinegar with one part warm water in a spray bottle if you're dealing with a hard-to-remove rust stain. Spray the solution onto the area and wait six to eight hours. Rinse the area thoroughly and repeat Step 1.
Pour undiluted distilled white vinegar onto a cloth and lay the cloth on the area if you still can't remove the stain or you're dealing with thick mineral deposits. Wait four to six hours. Rinse thoroughly to remove all of the vinegar and then try general cleaning again if necessary.
Contact the manufacturer of your brushed nickel finish product. Ask the manufacturer to recommend a cleanser or rust removal product. Try that product to remove the rust.