A carpet cleaner will never take the lanoline out of a wool carpet. It takes large scouring machines in a factory to reduce the lanoline on a wool fibre to produce a carpet. Remember raw wool off a sheep is very greasy. If you have a nylon carpet with a stain preventer coating, this will help the carpet to be easier to clean. A good coating should stay on for five years. Some other carpet cleaning companies may use excessive chemical in the extraction with no preparation, this may lead to sticking residues drying on the carpet and pre-soiling taking place.