A separator unit is a cleaning auxiliary tool to be inserted into an air/water feeding cylinder. The separator unit includes a partition plate for partitioning an air feeding conduit side and a water feeding conduit side, and two elastic members in an air/water feeding cylinder. The two elastic members are arranged at an outer circumferential side of the partition plate. When an internal pressure on the air feeding conduit side corresponds to an internal pressure on the water feeding conduit side, the elastic members are spaced apart from an inner wall of the air/water feeding cylinder by a predetermined distance, and when one of the internal pressures on the air feeding conduit and the water feeding conduit becomes higher than the other, one of the elastic members is deformed by receiving the higher internal pressure and comes in close contact with the inner wall of the air/water feeding cylinder.
