Cristyn Rybak of Woodbury needed a carpet cleaner stat. Her greyhound had gotten into a scrape and dripped blood on the dining room and bedroom carpeting. By the time she got back from the vet, the spots were dry.

A Bissell carpet cleaner she owned got out most of the stains, but stubborn shadows remained. Rybak called a carpet cleaner that had a coupon in a direct-mail promo. "Only $6 per room," was the pitch.

Typical of many low-ball carpet cleaners, the bid changed after the cleaner got to her home. Cleaning three rooms of less than 800 square feet, the bid came to $500. Rybak said she wasn't going to pay that much. Like a bad infomercial, the cleaner asked, "What will you pay?" When she replied $100, the cleaner called his manager to apply pressure to Rybak. The cleaner handed over his cell phone with the insistent manager on the line, but Rybak stood firm. Finally, it was agreed that only spot cleaning would be done for $100.

After the cleaning, the blood stains vanished -- until the carpet dried and the cleaner was long gone.

Rybak wasn't about to call him back to complain. "I didn't want him back in my house," she said. Rybak got out her Bissell shampooer again and after repeated efforts, got out the spots on her own, in addition to a new spot the cleaner created where he sat his dirty tank down on the hallway carpet.

Thanks to bad experiences like Rybak's, carpet cleaning ranks in the top 5 percent of complaints against service providers and retailers, said Barb Grieman, director of bureau services for the Minnesota/North Dakota division of the Better Business Bureau. The office had 55 complaints about carpet cleaners in 2005. Making matters worse, carpet cleaners settle only about half of their complaints, which is low, said Grieman. Common complaints include poor cleaning and spot removal, damage caused by cleaning equipment, overcharging, not moving furniture and not showing up for the appointment.

Reputable carpet cleaners say that while everyone likes to save a buck, a less than competent firm can cause permanent damage from overwetting, poorly mixed chemicals or improper brushing.

To avoid getting taken to the, er, cleaners, Consumers' Checkbook, a nonprofit, biannual consumer publication that accepts no advertising, suggests comparing prices by asking the price per square foot (typically ranging from 15 to 50 cents per foot). Some will charge by the area or room but ask them to define "area." Also ask for common add-on charges. Typically, spot-treating is included in bids, but not always. Stairs are extra.

Don't pay for add-ons such as deodorizers unless you have a clear need for them due to pet stains or smoke. You may want a fluorochemical-based soil protector such as Scotchguard, not a silicone-based treatment that can attract more soil after the application. New carpets treated with stain-protectors at the mill lose the protection in two to four years, but if the carpet is nearing replacement, don't pay extra.

Generally, the best cleaners use a truck-mounted hot water extraction system, also called steam cleaning. The most effective systems are powered by the engine in the truck rather than your home's electrical system, according to Checkbook.

John Ewoldt • 612-673-7633 or jewoldt@startribune.com. His articles are online at www.startribune.com/dollars.