Carpets can be cleaned well with the right cleaning method. Manufacturers recommend methods depending on the carpet fiber, usually wool, polyester, olefin or polypropylene, nylon, silk, cotton or a blend of two or more of these.
Carpet cleaning isn't such a big chore as long as you ensure that supplies and machinery are safe for the carpet and the individual who does the cleaning is qualified.
Just as carpet manufacturing has evolved, so has carpet cleaning. Most manufacturers recommend 'carpet steam cleaning' for cleaning modern-day carpets.