The system contains a molded plastic reticulated tray composed of a continuous rib that forms a tray rim and a plurality of intersecting ribs defining relatively large openings therebetween. The intersecting ribs are dished and having opposite ends connected to the continuous rib at spaced apart locations therealong. The plurality of intersecting ribs have rounded surfaces so that a fluid sterilant directed at the plurality of intersecting ribs from the outside, upon flowing through said openings, will follow and intimately contact said rounded surfaces to the tray interior so that those surfaces are cleaned thoroughly.