A flexible hose is attached to a suitable mixer tap. The other end is fitted with a garden-hose-type pistol-grip that has an extention containing a small water turbine or positive-displacement motor. This turns a roughly hemispherical brush at the end of the device.

The turbine or motor is sized to make the most of the available water pressure. When the trigger is squeezed the brush spins rapidly, though without much torque, while releasing a relatively small amount of water between the bristles of the brush. With the odd drop of washing-up liquid here and there it should make light work of the dishes, especially pernickety things like glasses that are just slightly taller than one’s fingers are long.

A useful feature would be a bypass valve (thumb-controlled?) that makes water directly available for rinsing, without having to change implements.