I seem to be getting plagued with beige carpets recently, and i done a luxury apartement the other day...with a beige carpet...The traffic lane in the hallway was pretty bad, and was practicaly black in places, down to the backing...I presprayed quite liberaly in these areas, and agitated, as you do..and used fibre & fabric rinse as a final treatment....the results wernt amazing, and i reset the pile, so that the remainder coulnt be seen that easily..there was still darkness visable, and i'm not happy with the results, even though the customer was very pleased....does anyone know how , or using what, i could have completely removed the offending residual darkness?