When carpet is made, it has two protective properties. One is a “dye blocker” or “stain resist” property. This is simply a clear dye that fills in the empty dye sites, so that it is difficult for a spill or spot to penetrate the fiber. The second is a “soil resistor” like 3M Scothgard or DuPont Teflon. This is a product that is sprayed on the yarn and baked on at a high temperature. This helps to resist against common dry soil, and to act as a barrier between the spill and the dye blocker. After a period of about 2 to 3 years, depending on traffic, the soil resistor wears off and needs to be reapplied. After applying DuPont Teflon to the carpet, more dry soil will be removed with vacuuming.
Most spots will be removed with just water. With furniture we have a protector that also resists spills & body oils so that the material will retain it color and texture longer.