An actuation assembly for an oral irrigator includes a bezel secured to or formed as part of a housing of the oral irrigator, an actuator operably connected to the bezel and moveable relative thereto, and an augmentation fluid positioned between the bezel and the actuator. The augmentation fluid modifies a frictional relationship between the bezel and the actuator to provide a predefined resistance force between the actuator and the bezel as the actuator is rotated relative to the bezel.