Abstract: A shampooing tool has a “clam-shell” design for trapping the components of the tool between the complementary mating halves of the housing. The components include a barrel disposed in the upper portion of the housing and connected to a pressurized water source, a trigger depending from an enclosed hand grip, a normally-closed spring-loaded valve disposed in the front portion of the housing and connected to the trigger for movement in unison, and a cylinder within the lower part of the housing, the cylinder having a pressurized liquid detergent and further having a discharge port leading to a valve seat. When the trigger is depressed, the valve is unseated; and the liquid detergent, under pressure, flows into a tube running substantially parallel to the barrel.