There are a lot of carpet-cleaning products on the market that claim to do the same job as professional carpet-cleaning services at a fraction of the price. But choose carefully—many of these products are less effective than they claim to be, and some can do permanent damage to carpets. The best options…

SMALL STAINS

Spray-on carpet spot-and-stain removers are an affordable solution for most stains, but effectiveness varies greatly from product to product. I’ve found Carpet CPR ($9.95 for a 24-ounce bottle, LeatherCPR.com)…Folex Instant Carpet Spot Remover (around $8 for a 32-ounce bottle, FolexCompany.com)…and Spot Shot ($6.99 for a 22-ounce bottle, SpotShot.com) to be effective. All are available on Amazon.com.

Warning: Handheld carpet spot- cleaning machines can do a nice job cleaning small stains. Trouble is, they create an area of clean rug that’s just as obvious as the stain they removed, so I don’t recommend them. And never use laundry spot remover, laundry detergent, shampoo or dish soap on carpet stains. These contain detergents and other cleaners that you will never completely get out of your carpet. Dirt and grime are likely to stick to this detergent residue, making the carpet appear even dingier.

STUBBORN STAINS AND HIGH-TRAFFIC AREAS

A hot-water-extraction machine—often called a steam cleaner—is the most effective do-it-yourself option for cleaning larger areas and stubborn stains. These apply hot water from your tap and/or cleaning chemicals to the carpet, then use a powerful vacuum to suck the liquid back out. You can rent one for around $25 a day. Renting saves a considerable amount of money. A home with 800 square feet of carpet might cost $200 to clean by a pro, so $25 for a day’s rental and a $10 bottle of spot-and-stain remover represents a savings of $165.

Lean toward the Rug Doctor brand if you’re renting a machine—it’s very effective (RugDoctor.com).

Or you can buy your own hot-water-extraction machine for less than $200. I like Hoover or Bissell models. Example: The Hoover Max Extract Dual V WidePath Carpet Washer (recently available for $169.99 on Hoover.com).

When you use a hot-water-extraction machine…

Put only hot water in the tank, not chemical cleaners. The chemicals used in these machines often leave a residue behind that can attract grime. If your carpets are stained or have become discolored in high-traffic areas, instead pretreat the affected areas with a carpet spot-and-stain remover, such as those mentioned above. Allow this to remain on the carpet for the amount of time recommended on the bottle, then use the hot-water extractor to apply water only.

Limit the amount of water you apply, then remove every drop. Make only one or two passes when applying hot water, but continue to make passes to extract water until you see no more water coming up the unit’s hose. This could take a while—using a hot-water-extraction machine can be a lengthy chore—but if water is allowed to remain in the carpet, it could lead to mold or mildew.

If you rent a hot-water-extraction machine, take it outside and run hot water mixed with vinegar through it to clean it out before using it on your carpet. The people who rented it before you may have used chemicals in it that could damage your carpet.

If you own a hot-water-extraction machine, empty the tank after each use, dry the tank’s interior and leave the top of the tank off when you store the machine. This reduces the odds that mold or mildew will develop inside the tank, then be transferred to your carpet.

If you use a hot-water-extraction machine to treat a stain within minutes of the stain occurring, start with cold water before switching to hot. Using hot water initially could set the stain.

Warning: Other types of do-it-yourself devices and products that claim to compete with hot-water extraction for cleaning large areas of carpeting are best avoided. There are dry powders and foams designed to be spread on carpets, then vacuumed up. Trouble is, it’s impossible to vacuum up all that’s applied. The remainder will work its way down into the carpet and turn into a pasty grime-holding residue the next time the carpet becomes wet, such as when you later use a hot-water-extraction machine. Carpet shampooers are best avoided, too, because they can be abrasive to carpet fibers.

WHOLE-HOME CARPET CLEANING

If you have many large carpeted rooms that require cleaning or want your carpet to be as clean as possible, it’s worth hiring a professional carpet cleaner. The pros have cleaning equipment that can heat water to a much higher temperature than the hot water do-it-yourselfers use, and they have vacuums that can extract water more effectively.

The typical pro charges 20 to 30 cents per square foot of carpet. Some carpet-cleaning pros offer coupons in local publications or on their Web sites that can reduce prices.

Warning: Before hiring a professional carpet cleaner, confirm that he/she has a truck-mounted system. These produce the highest water temperatures and best water extraction. Confirm that the company carries liability insurance. Insurance protects you if your carpet or anything else is damaged, and it suggests that this is a legitimate professional.

CLEANING PET STAINS

Pet urine stains are best treated as soon as possible. First blot up all that you can with paper towels. Once you have done that, spray on a solution of one-third white vinegar and two-thirds cool water. Again blot, blot, blot. Allow to dry, and then treat with carpet spot remover if there is a stain.

For odor, try Odorzout. It is a dry product that eliminates odor by absorbing it rather than covering it up (available on Amazon.com). Use according to directions.

If you own a carpet-cleaning machine, now is the time to use it. Blot up all the urine you can, then treat with the vinegar/water mixture and extract it using cool water.

Some pet “messes,” including vomit and feces, sit on top of the carpet. These require a special cleaning strategy.

Don’t rush to scrape up the mess as most people tend to do. That smears the material deeper into the carpet fibers. Instead, pour a significant amount of baking soda onto the mess—cover it completely. Use a whole box if necessary.

The baking soda should draw the moisture out of the mess until the material is dry enough—you probably want to leave it overnight—to be gently lifted up with a paper towel, plastic bag or a plastic putty knife. Next, vacuum up the remaining baking-soda-and-mess residue using your vacuum’s hose with no attachment—a hose alone provides the strongest suction on a vacuum cleaner. If there’s discoloration, use one of the carpet spot-and-stain removers listed in the section about small stains.

EVERYDAY CARPET CARE

Your carpet won’t require cleaning as often if you vacuum at least twice a week. Most of the dirt will be vacuumed away before it has time to work its way into carpet fibers. Replace your vacuum bag when it’s half full—the fuller the bag, the less suction your vacuum has. If your vacuum has a canister rather than a bag, empty it after one or two uses.