Abstract: A device positionable upstream from a shower nozzle for dispensing solid, water-soluble or water-dispersible materials is disclosed. The device includes a tubular body (1) of which a first end (2) has a circular flange (3) and comprises an internal thread (4) defining a first shoulder (5), and a second end is threaded; and a cylindrical coupling portion (6) comprising a circular abutment (7) and two threads on either side thereof, i.e., a first or outer thread (8) with a diameter suitable for engagement with a shower hose, and a second or internal thread (9) with a diameter suitable for screwing said portion (6) into the second end of the body (1). The end of said internal thread forms a second shoulder (10). A chamber (11) is defined inside said body (1) between the first (5) and second (10) shoulders, whereat the wall of said body (1) comprises a window (12) for inserting a solid material into said chamber (4).