When we had carpet, we tried to have it professionally done once a year. Used ChemDry for years, didn't get the carpet as clean, but it resisted dirt better. Switched to steam cleaning for a while as the carpet got older, then got a Bissell. Now we have laminate. Despite the cleaning, it was amazing how much fine dirt like material was under the carpet after 34 years. Flooring guy said our carpet was very clean, but no cleaning system gets the dirt below the backing.