Our fabric stain remover set is carefully formulated with fabric stain removers: citric acid and sodium gluconate and powerful stain removers: nonylphenol polyether-9 and tetrasodium glutamate diacetate. Designed specifically for easy removal of stubborn stains. The usage method is extremely convenient: 1. Apply the fabric stain remover directly to the rust (or the stain that needs to be treated). After the rust disappears wash and dry the clothes immediately. For more stubborn or dry stains use a strong stain remover. Apply the cleaner directly to the stain and gently wipe it allowing it to take effect for a period of time. 3. Finally rinse the treated area with clean water to remove any residues. And it can deeply remove stains while protecting clothes without causing any damage.