A cleaning device (14) for cleaning mop material (33) which freely hangs from a holder (31,32), having an opening (15) in which the hanging mop material (33) is receivable, including a pair of bristle carrying parts (22, 24), each of the bristle carrying parts (22, 24) being rotatable about a respective axis (22a, 24a) by at least one motive device in opposite senses of direction such as to draw the hanging mop material (33) between the bristle carrying parts (22, 24), whereby bristles carried by the bristle carrying parts (22, 24) engage the mop material, and a method of cleaning mop material which freely hangs from a holder, using the cleaning device (14), the method including resisting the drawing-in of the mop material between the bristle carrying parts (22, 24), so that the bristles act on and brush the mop material.