The term "ingrained dirt" is used to describe dirt that has been pushed so far down into the pores or fibres of a surface that standard cleaning methods fail. Ingrained dirt is commonly found in rugs, children's car seats, concrete floors, and other high traffic areas. It is possible to remove ingrained dirt and return your surfaces to their original glory, but to do so requires some special attention.
Spray a cotton cloth with foaming cleanser, and wipe the stained area. Examine the cloth to determine how much of the dirt is surface dirt. If any of the dirt comes off onto the cloth, rinse out the cloth, and repeat the process until surface dirt is no longer transferred.
Spray the area of ingrained dirt with the foaming cleanser and use a soft-bristle nail brush to work the foam into the surface. Scrub the surface using small circles. Allow the product to sit for at least 30 minutes, and then repeat.
Fill a spray bottle with clean water, and spray the area heavily. Immediately use a wet/dry vacuum cleaner to remove as much of the water and dirt as possible.
Repeat Steps 1 through 3 until the ingrained dirt is no longer present. Allow the surface to dry thoroughly before use.