The fabrics in our home become dirty with use even when we don't see the dirt. Hand lotion, sweat, spilled drinks, pet dander, dead skin, dust, dirt tracked in on shoes and bare feet, oil and grease from spilled food. oil and grease from cooking fumes, pet hair, people hair,
Carpet & Upholstery Cleaning Professionals Company based in Liverpool etc.
There are special soap formulas and suction machines with and without heating elements you can buy or rent to periodically clean upholstery and carpeting.