The best way to really clean carpets. (Up Front).

The last time we tested deep-cleaning machines for carpets, we found that most machines were mediocre at best. Our advice then: "Before you shell out a couple of hundred dollars. be sure a deep-cleaner is what you need. Rent first."

Things have changed a little. Our latest tests pitted three leading vacuum-sized appliances against a rental unit available at the supermarket and a nationwide cleaning service.

Who won? Judged strictly on removing soil, the pros from Stanley Steemer took the honors. But most of the products and services have something to recommend them. We looked at price and made judgments on cleaning and dryness (the amount of water left in the carpet afterward).

Professional cleaning. Stanley Steemer got test carpets at a staffer's home the cleanest. But it's expensive. We paid $181 for two rooms and a hallway (Prices vary from one area of the U.S. to another and with the number of rooms being cleaned.) Because the service wasn't tested in the lab, we couldn't measure the amount of moisture left in the carpets.

Vacuum-sized cleaners. These gave mixed results in our lab tests, All work by scrubbing in a solution of water and detergent then vacuuming up the water and dirt. All are expensive and take ...