Amazon.com: Spotless Stainless Citric Acid Rust and Rust Stain Remover for Stainless Steel - This Quart (32 Ounce) Gel Remover and Protectant is enough Stainless Steel Stain Remover for Routine Rust Removal,
DIYChemicals Phosphoric Acid 85% – Rust Remover, Wood Stain Remover, pH Control, High Purity Orthophosphoric Acid for Metal, Fertilizers - Made in USA - 1 Pint (16 fl oz)