Abstract: A hand-washing system for washing fingernail beds and cuticular regions of human fingers and thumbs (collectively “digits”). The hand-washing system includes a work enclosure for containing ones of the digits and a high-velocity, high-flow water spray during a washing operation. The work enclosure defines an interior space, part of which defines an energy-dissipation region that, during use, provides a water reservoir for dissipating energy in the high-velocity, high flow water spray. The work enclosure includes a high-energy spray nozzle and a digit portal sized to receive the four fingers of one hand simultaneously in closed-fingered, upwardly-curled configuration. A mixing valve may be provided to allow a user to adjust the temperature of the water during washing. A quick-disconnect fluid-coupling assembly may also be provided and be used to quickly select between work enclosures of differing size.