The damage amounted to a synthetic carpet fibers making them easily hold dirt. With HG carpet and upholstery cleaner (HG product 95) is removed the dirt and filled up the uneven fiber surface with a dirt-repellent layer.
Even with a woolen carpet occurs in the long run the like. The natural lanolin namely slowly disappearing. HG carpet and upholstery cleaner fills it back in with dirt-repellent material.
Treat the stain beforehand with HG stain spray. Then HG carpet and upholstery cleaner make every row with a special machine and direct extraction or rub with a brush. Wipe dry with a terry towel. One liter is good for 30 square meters.