Dry cleaners have traditionally used perchloroethylene to remove stains from our laundry. It’s certainly effective, but "perc" is a known skin and lung irritant. A new trend toward "green" cleaning has many dry cleaners moving away from chemicals – instead using a liquid silicone made from sand. Rene Gutel (rhymes with Mattel, the toy company) looks at so-called “environmentally friendly” dry cleaning.