Abstract: The present invention is directed to a waste treating reservoir for treating waste collected using an associated suction system. A disposable receptacle connected to an associated suction system includes a sealed chamber such as a liner and a lid with a pour spout. The waste treating reservoir includes a closed container with an open mouth for storing a waste treating agent. A cylindrical wall forms a diffuser cap and has an open end portion and a substantially closed end portion. The closed end portion has a plurality of apertures opening radially through the cylindrical wall. The open end portion of the cylindrical diffuser cap fits telescopically over the open mouth of the agent container. The reservoir system further includes a double-walled sleeve having an inner wall and a generally concentric outer wall for attaching the combined diffuser cap and agent container to the spout of the disposable receptacle lid.