Before you give up all hope of ever getting that perspiration stain out of your good white dress shirt, try this: Crush two aspirins and mix the powder in 1/2 cup warm water. Soak the stained part of the garment in the solution for two to three hours.
Pretreating clothes with a paste made from 4 tablespoons baking soda and 1/4 cup warm water can help vanquish a variety of stains. For example, rub it into shirts to remove perspiration stains; for really bad stains, let the paste dry for about two hours before washing. Rub out tar stains by applying the paste and washing in plain baking soda. For collar stains, rub in the paste and add a bit of vinegar as you’re putting the shirt in the wash.
Tenderize away hard-to-remove perspiration stains. Before you wash that sweat-stained sweatshirt (or any other perspiration-stained garment) dampen the stain and then sprinkle some meat tenderizer on it. Then just wash as usual
Salt’s the secret to getting rid of those stubborn yellow perspiration stains on shirts. Dissolve 4 tablespoons salt in 1 quart (1 liter) hot water. Just sponge the garment with the solution until the stain disappears.
Want to see those sweat marks disappear from shirts and other garments? Just pour a bit of vinegar directly onto the stain, and rub it into the fabric before placing the item in the wash. You can also remove deodorant stains from your washable shirts and blouses by gently rubbing the spot with undiluted vinegar before laundering.