If these are loose rug you can FREEZE the bad boys and use no toxic chems at all!
I had a museum currator teach me this years ago.
1. Freeze in a deep freeze for 1 week
2. pull out for one week into a warm enviroment, but keep rolled up in the dark.
3. Put back into the freezer for one week
The reason you want to pull it out for a week is because all the eggs may not have been killed off on the first freeze, but the emergence into the warm air will trigger any live eggs.
This always works for us and I charge out at 1.25/sq. ft.
I use an old 6' long deep freezer.
This of coarse has no residual effect, but it is very nice to let the client know there is no chems at all.
I am a firm believer that the client needs to know how to avoid a re-infestation.
The best thing a client can do is vacuum both sides of a rug at least once a month.
Moths love to lay their eggs in dark areas and cant be disturbed.
One more thing that makes a big diff is to use/store the rugs in a dry area. A moist, dark and warm room with a yummy wool rug is irresistable to a moth.
Here is something I clipped from a very good web site on wool rug care!
http://www.jacobsenrugs.com/care.htm#mothsMoth Damage
Flying clothes moths do not eat your rugs, but the females do lay hundreds of eggs each, and the eggs hatch into larvae that consume wool, fur, feather, and silk fibers. Moths and their larvae thrive in dark, undisturbed areas where a rug gets little traffic and is not often vacuumed. A bad infestation sometimes leaves a cobweb-like veil in the area of the damage, along with fine, sand-like debris. An infestation often involves more than one rug, and can spread to (or from) woolens or furs hanging in a closet or sweaters stored in a drawer. A rug damaged by moths is not difficult to repair, but reweaving a large area of the rug can be expensive.
The life cycle of the clothes moth
(Not to scale)
To identify the presence of moths, look for one or more of these signs (see pictures here):
flying moths -- the common clothing moth (tineola bisselliella) is the villain. It's small, 3/8" long or less, and is usually silvery tan or soft brown in color. This moth flies slowly but with a rapid flutter of small wings. If you try to snatch one out of the air, the clothes moth folds its wings and drops to the floor.
bare spots in the pile -- often moth larvae will prefer the taste of one color yarn over another, and so the bare spots may involve some specific colors but not others.
webs -- white gossamer filaments covering a patch of the rug's pile (often only present with a bad infestation).
cocoons -- 1/8" diameter x 1/2" long slightly fuzzy cylinders usually the same color as the rug's pile (larvae camouflage their cocoons to blend in with the color of the wool that surrounds them).
larvae in the pile -- slender, white, worm-like moth larvae about 3/8" long can sometimes be seen just after hatching, before they've constructed cocoons. It is the larvae that actually eat the wool.
sand-like particles down in the pile of the rug -- this material, often tan or brown in color, regular in size, and granular in look, is the excretion of the larvae.
broken/loose plies -- where the larvae have chewed through yarn overcastings or bindings.
To prevent moth damage:
Vacuum the entire face of the rug weekly if possible. At least several times a year, vacuum the back side of the rug and the pad and floor underneath. If the rug is too large to handle, flip the edges over, and vacuum at least one to two feet in along the borders on the back side of the rug. The corresponding areas on the pad and floor should also be vacuumed.
Be aware that moth balls, flakes, or crystals (naphthalene or paradichlorobenzene) are ineffective in moth control for rugs. These materials act only as a minor repellent to moths. They do not kill moth larvae, and the naphthalene odor can be unpleasant and difficult to remove from the rug. Cedar scent is useless as a prevention for moth damage.
Any place the vacuum cannot reach, such as areas of the rug under furniture, or a rug hung on the wall, can be sprayed with a household, non-staining insecticide made for the purpose. Most of these products contain pyrethrins (a class of insecticide originally extracted from the flower heads of chrysanthemums) among the active ingredients. Although poisonous to many varieties of insects, pyrethrins break down quickly after application and are considered safe for use in the home. BE CAREFUL IN CHOOSING AND APPLYING ANY INSECTICIDE. Choose a product designed for the intended use and follow directions for application, storage, and disposal carefully.