An oral irrigator handle (100) for receiving an oral hygiene agent is described. The handle (100) may be connected to a countertop oral irrigator or may be a portion of a handheld oral irrigator (10). The handle includes a chamber (124) for receiving the oral hygiene agent, where the chamber body positioned within the fluid path of the handle. Fluid flowing into the handle, flows into the chamber, allowing the fluid to intermix with the agent, and then flows from the chamber to a tip connected to the handle (100).