A rinsing instrument (1) is described, comprising a vibration part (30) and a spraying part (20) which can be coupled to each other. The spraying part comprises: a hollow cylindrical body (21) with an input end (23) and a narrow needle (25); an axially displaceable piston (22) arranged in the interior of the body, which at its free side directed away from the spraying mouth is provided with a coupling member (27) for coupling to the vibration part, for instance a threading. The vibration part comprises: a housing (31) which at an end is provided with a coupling member (32) for coupling to the spraying part, for instance a threading; a vibration generator (34) mounted in the housing, for instance a motor; a battery chamber (39) for receiving a battery (35) providing electrical supply to the vibration generator; a user-controllable switch (36) mounted in the housing for actuating the vibration generator.