Abstract: The invention relates to a method for the mechanical treatment of a reusable medical product. Said method comprises the following steps: a) the medical product (11) is placed in a closable cassette (14) comprising connections for the supply and discharge of a treatment medium, and comprising at least one inside connection to which rinsable cavities and/or channels for the medical product are connected in such a way that the treatment medium can pass through said cavities and/or channels, b) the cassette (14) is closed, c) a fresh, liquid treatment medium is supplied to the supply connections of the cassette (14), the medium in the cassette (14) coming into contact with the medical product and the treatment being carried out, and the treatment medium flows through the cavities and/or channels; d) the treatment medium is discharged from the discharging connections; and e) the discharged treatment medium is rejected, the temperature of the treatment medium not exceeding 100° C.