It is very important to dry rugs and carpets as soon as possible to prevent mildew, a spreading gray-white mold that stains and rots fabrics. Pull up waterlogged rugs immediately to prevent further damage to the floor. If possible, dry small rugs outdoors in sunlight.
To get air and heat to carpets, open windows if weather permits, or use household electric fans, crop drying fans or electric lights suspended in coat hanger "nests". Do not try to vacuum, sweep or shampoo carpets until they are thoroughly dry.
2. Sweep or vacuum
After the carpet is dry, thoroughly vacuum or sweep to get rid of dirt and debris. Move the vacuum cleaner slowly to pick up more dirt. Clean off as much crusted dirt and sediment as possible before shampooing.
3. Shampoo (Some rugs may shrink when shampooed)
Use a commercial rug shampoo or make your own shampoo by mixing 1/4 cup mild dry detergent and 1 cup warm water in a pail. Beat the mixture with an egg beater until it forms a stiff foam that looks like whipped cream.
With a sponge, rub suds on a small patch of carpet (about 2 feet square) with a light circular motion. Use only the foam. (If foam disappears during the shampooing process, beat the mixture again.) Work suds in with sponge. Use a stiff bristle brush if carpet is deeply soiled.
Dip sponge in a weak chlorine solution (1/4 teaspoon Clorox to 1 cup water). Wring out sponge and wipe suds off carpet.
Rinse several times with clear water, wringing most of the water from the sponge each time. Change the rinse water as it becomes dirty. Use as little water as possible on the sponge since water will weaken carpet backing.
Blot up remaining moisture with bath towels or other soft absorbent material.
Apply lather to another small area, overlapping the first. (overlapping helps prevent streaking when the carpet dries). Rinse and blot dry. Continue until the entire surface has been cleaned.
After shampooing, dry rugs or carpets quickly. Hang rugs on line if possible, or lay them out flat in a warm dry place. An electric fan will speed up drying.
Carpets and rugs should be thoroughly dried. Even though the surface seems dry, any moisture remaining at the base of the fiber tufts will cause mildew or rot. If you must walk on the carpet before it is dry, put down brown paper. Vacuum when dry, and brush the nap in one direction.
Some types of machine-made pile rugs may need resizing to make them lie flat. To resize a rug:
a. Lay the rug face down on papers where it can remain undisturbed for several days.
b. Check to be sure rug is straight. Tack it down at intervals.
c. Dissolve 1/2 pound granulated glue in 1 gallon boiling water.
d. With a whitewash brush or whisk broom, brush hot glue over the back of the rug. Do not use so much glue that it will soak through the right side of the rug.
e. Let the glue dry thoroughly.
Source: MSU Extension