an improved power - driven brush assembly is disclosed , useful for cleaning the interior surfaces of ducts , pipes , and other similar structures . the apparatus comprises a cable having a brush at one end , and a motor at the other end for spinning the cable and the brush . a casing surrounds the cable , allowing a fluid to be injected through the casing to the brush . a fluid directing assembly at the end of the casing near the brush allows fluid to the be injected into the duct in a desired direction , to flush particulate matter from the vicinity of the brush .