A flow-through rack assembly (14) includes porous hangers (44) which support items to be decontaminated within a decontamination chamber (12). A plurality of nozzles (16) spray a decontaminant fluid, such as peracetic acid, over the items. The rack assembly includes tubes (42) which convey a portion of the decontaminant fluid under pressure to internal channels (52) of the porous hangers. The fluid permeates the hanger surface, flowing over regions of the items which are in contact with the hangers. The rack assembly ensures decontamination of those regions which may be otherwise inaccessible to fluid sprayed from the nozzles.