Argyrol
Argyrol stains must be treated while still fresh. Proceed as follows:
Pepsin.—Sponge with warm water to remove any argyrol that has not soaked into the cloth. Then sprinkle powdered pepsin over the dampened stain. Work it well into the cloth, let stand a half hour or longer, then sponge with water.
Iodine and sodium thiosulfate (“hypo”).—After the above treatment, put a few drops of tincture of iodine on the dampened stain with a glass rod. Let stand for 10 or 15 minutes; then sponge with a solution prepared by dissolving several crystals of sodium thiosulfate in ½ cup of water. Rinse well in water.
To bring back the color changed by an acid, hold the dampened stain in the fumes from an open bottle of ammonia water.
Blood
Blood stains will usually come out if sponged or washed in cold or lukewarm water first. Never use hot water; it sets the stain.
Cold or lukewarm water.—For stains on silk or wool, sponge with cold or lukewarm water. For washable material, soak the stains in cold water until they turn light brown in color; then wash in warm soapy water. If the stain is an old one and has dried, it may help to add 2 tablespoons of ammonia water to each gallon of water used for soaking. Strong salt water (about 2 cups of salt to 1 gallon water) is also good to loosen the stain.
Hydrogen peroxide and sodium perborate.—If the above treatment does not completely remove the stain, sponge with hydrogen peroxide. Or sponge with a mixture of 1 level teaspoon sodium perborate to 1 pint hydrogen peroxide. If the stain still shows, cover the dampened spot with powdered sodium perborate and let stand an hour. Rinse thoroughly. These bleaches will not harm the cloth, but before using test for colorfastness on a sample of cloth or on an inner seam of the garment. If the color fades, do not use the bleaches; just dampen the stain and spread in the sun to bleach.