A mechanism for intermittently wetting a cleaning tape (13) contained within a tape cassette housing (11) is located within the housing at a position along the tape path prior to the tape exit (14) in the direction of forward motion of the tape. The mechanism comprises a star wheel (21) rotatably mounted adjacent the inside surface (24) of the cleaning tape whose arms (23) are driven by friction with the tape to rotate the star wheel, and a lever (22) pivotted adjacent the same surface of the tape as the star wheel, the lever being intermittently deflected in a first direction of rotation by engagement with successive arms (23) of the star wheel as the star wheel rotates during forward motion of the tape. A wetting member (20) is mounted adjacent the outside surface of the tape opposite the lever, and each arm (23) of the star wheel during its engagement with the lever (22) effects sufficient deflection of the lever in the first direction of rotation that the lever bears against and deflects the tape (13) outwardly to such an extent that the outer surface of the tape is brought to bear against the wetting member (20). The lever (22) has sufficient resilience to permit each arm (23) to disengage the lever during further rotation of the star wheel (21) after the tape has been brought to bear on the wetting member, whereby the lever (22) returns in the opposite direction of rotation for re-engagement of the first portion by the next arm.