A system, comprising: an enclosure; a drum housed within the enclosure; a mixing unit, housed within the enclosure, separate from the drum, and in fluid communication with the drum; a water supply unit coupled to the mixing unit; a reservoir having a conduit configured to fluidly couple the reservoir to the mixing unit; a container connecting assembly configured to fix a spout of a container to the reservoir; and viewing ports for observation of amount of liquid wash aid stored in the reservoir, wherein: the container is removably fixed to the enclosure, or the container is removably fixed to a supply module and the supply module is removably fixed to the enclosure, wherein the viewing ports are on: the enclosure, if the container is removably fixed to the enclosure, or on the supply module, if the container is removably fixed to the supply module; wherein the reservoir is: located in the enclosure and detachably coupled to the enclosure, if the container is removably fixed to the enclosure, or included on an underside of the supply module and detachably coupled to the supply module, if the container is removably fixed to the supply module; and wherein the reservoir is partially or entirely transparent, to permit observation of a level of the reservoir's contents by the viewing ports. an enclosure; a drum housed within the enclosure; a mixing unit, housed within the enclosure, separate from the drum, and in fluid communication with the drum; a water supply unit coupled to the mixing unit; a reservoir having a conduit configured to fluidly couple the reservoir to the mixing unit; a container connecting assembly configured to fix a spout of a container to the reservoir; and viewing ports for observation of amount of liquid wash aid stored in the reservoir, wherein: the container is removably fixed to the enclosure, or the container is removably fixed to a supply module and the supply module is removably fixed to the enclosure, the container is removably fixed to the enclosure, or the container is removably fixed to a supply module and the supply module is removably fixed to the enclosure, wherein the viewing ports are on: the enclosure, if the container is removably fixed to the enclosure, or on the supply module, if the container is removably fixed to the supply module; wherein the reservoir is: located in the enclosure and detachably coupled to the enclosure, if the container is removably fixed to the enclosure, or included on an underside of the supply module and detachably coupled to the supply module, if the container is removably fixed to the supply module; and wherein the reservoir is partially or entirely transparent, to permit observation of a level of the reservoir's contents by the viewing ports. the enclosure, if the container is removably fixed to the enclosure, or on the supply module, if the container is removably fixed to the supply module; wherein the reservoir is: located in the enclosure and detachably coupled to the enclosure, if the container is removably fixed to the enclosure, or included on an underside of the supply module and detachably coupled to the supply module, if the container is removably fixed to the supply module; and wherein the reservoir is partially or entirely transparent, to permit observation of a level of the reservoir's contents by the viewing ports.