Abstract: A method for removal of undesirable foreign matter from the interior of existing duct systems. The method comprises the insertion of a plurality of members into a stream of air within the existing duct to loosen the dirt adhering to the duct walls. The members are capable of receiving and holding a static electric charge on their exterior surfaces so that when the members are agitated within the stream of air and against the duct, a static electrical charge is placed thereon. The electrical charge causes a portion of the foreign matter to be attracted to and adhere to the members. The stream of air with the members and loose foreign matter entrained therein is then removed from the duct.