like i said if it is firearms related, its clp or oil and carbon/powder residue, get a gallon of zep citrus to start, spray it, then lightly brush with a soft bristle brush, then extract...then repeat. if it is coming off on your bare hand then it will clean up no problem, it may just take a few extra passes. if you dont have an extractor then break out a ton of terry cloths, spray with citrus degreaser, rub the pile with the terry cloth, constantly change to a clean portion of the cloth and once it is mostly out have a spray bottle with distilled water on stand by, lightly mist the area and rub again with the terry towels. it will come clean, keep us posted