After your chemical warfare has done its job, wash the garment on cold with a regular detergent. Never put it in the dryer until you’re sure the stain is gone. Heat is the enemy! It will permanently weld the rust into the fabric, turning it into a modern art piece you can’t sell.
Effective Tips to Remove Rust Stains from Clothes - Your Ultimate Rust
Hold the shirt up to the light. If you still see a ghostly brown shadow, repeat the whole process. I’ve done it four times for a single sock—it’s a badge of honor, not shame.
