Pepsin and other enzymes
Enzymes will remove certain stains from all kinds of materials. You can buy pepsin, the best known of the enzymes, at the drug store. It softens stains containing albumin (found in blood, gelatin, glues, certain medicines, eggs, milk, and ice cream), so that they wash out in water easily. Pepsin will soften these stains, even after they have been set by heat or alcohol. First be sure there is no soap or other alkali on the stain, or the enzyme will not react. Then dampen the stain with lukewarm water and sprinkle with pepsin powder. Let it stand for half an hour, keeping the spot damp. Or mix the pepsin with water (2 teaspoons to 1 pint lukewarm water) and sponge the stain with it. Sponge or rinse well with water.
Soaps and synthetic detergents
Soaps and synthetic detergents (nonsoap cleaners) are helpful in removing grease and food spots, blood, and many other stains. For washing silks and woolens, select a mild soap. One with added alkaline salts may cause the colors to run and the cloth to become stiff and harsh. Also use a mild soap on all other delicate materials and on cotton, especially on those that are not guaranteed colorfast. If you are washing in hard water, add a water softener such as one of the special phosphates—sodium hexametaphosphate or tetrasodium pyrophosphate (sold under brand names)—which prevent the formation of hard-water scum. This scum is caused by the reaction of the soap and the calcium and magnesium compounds in the water. It settles on the clothes in gray or brown specks that are hard to remove.
Synthetic detergents come in powder, paste, and liquid form. Most of them suds and lather well, although a few clean without sudsing. They do not make a scum with hard water.
Synthetic detergents, like soaps, may be mild or alkaline. The mild synthetics are excellent for washing silks and fine fabrics, blankets, and sweaters. They are relatively safe for colors. The alkaline synthetics, which contain alkaline salts to aid in soil removal, are all-purpose washing agents for washing heavily soiled garments.
The nonalkaline detergents can be used in place of glycerine to loosen fresh tannin stains made by soft drinks and some fresh fruits. The other type should not be used because alkali tends to set tannin stains. Soap, even the mild type, is also alkaline enough to set these stains.
There are also special dry-cleaning soaps or benzene soaps, which, added to dry-cleaning fluid, aid in softening the stain and removing the dirt. Or, to soften a heavy grease or wax stain, put these soaps directly on the stain, especially on silk and wool cloth. Then rinse well in carbon tetrachloride, Stoddard solvent, gasoline, or benzene.
Stain-Removal Supplies
Keep all stain removers together on a handy shelf, but out of the reach of children. Label all the jars and bottles; be sure to mark “Poison” plainly on the poisonous ones. To have a complete shelf, you will need to keep at least three kinds of cleaning agents—bleaches, absorbent powders, grease solvents.