I’ve always recommended against the use of carpet cleaning with hot water extractors (also known as steam cleaners or carpet shampooers) because most of them leave the carpet damp, setting the stage for mold growth. They can also leave a sticky film on the carpet that just attracts more dirt.
Then I saw the Bissell ProHeat CleanShot deep cleaner. This system works much better than any steam cleaner that you can buy or rent. And, for about the same price as renting one, you can have your own to use whenever you want. (If you have light-colored carpets like I do, a deep cleaner will come in handy quite often!) Read more about Bissell deep carpet cleaners