A container for enabling fluid flow therethrough for cleaning or sterilizing of the contents, comprises a tray (10) and lid (20) and having respective bases (11, 21) and side walls (17, 27). The bases (11, 21) have perforations (12, 22) defined by elliptically shaped perforation walls (13, 23) with their major axes vertical to allow easy flow of the cleaning fluid through the container and minimum contact points with the contents or other containers. The internal corners (30) of the perforations (12, 22) in horizontal sections are smoothly curved to minimize debris or deposits collecting and resisting removal. A method of cleaning or sterilizing using the container is also described.
