Abstract: A cleaning apparatus for cleaning containers on a construction site comprises an armature having a cylindrical body with an end wall. The armature is covered with a scrubbing material and is constructed for attachment to a shaft rotated by a power source such as a hand-held power drill. The armature includes keying structure that precludes rotation relative to the shaft. In one embodiment, the legs of a stirring paddle at the distal region of the shaft are inserted into corners of a square cylindrical armature to key them together. In another embodiment, the armature is constructed of a circular cylindrical body with identical end caps attached thereto, and the end caps are keyed to the shaft. A user handle may be mounted on the shaft to provide better control of the apparatus during a cleaning operation.