How to Remove Sweat Stains From Cotton
- 1). Dampen a cloth with ammonia, if the stains are fresh. Apply the ammonia to the sweat stains by dabbing the stains with the cloth.
- 2). Wet another cloth with water, and then apply the cloth to the stains. The water will rinse the ammonia out of the cotton fabric.
- 3). Apply liquid enzyme detergent directly onto the sweat stains. Rub the detergent into the stains with your finger.
- 4). Launder the cotton fabric in a washing machine with hot water, and then inspect the fabric for remaining stains. If stains remain, repeat the process. Otherwise, allow the cotton fabric to air-dry.
Source...