a coiled clear plastic tube is disposed within a wire basket support and contains a liquid medication to be mixed with another liquid , such as water . the inlet end of the coiled tube is connected through a valve to a source of water pressure which serves as a motive force to drive the medication within the coiled tube to its outlet end . a portion of the water supply is diverted in the valve and is directed to a mixing valve to which is also coupled the outlet end of the coiled tube . a reduced diameter orifice controls the feed of the medication to the mixing valve such that the outlet of the latter provides a controlled mixture of water and medication .