A dedusting apparatus has a product outlet offset laterally with respect to a vertical line passing through the product inlet. The dedusting apparatus has a primary wash deck structure with a flow of air passing therethrough into the flow of product. Product discharged off the lower end of the wash deck passes into a Venture zone fed by a flow of air passing through openings in the support leg for the wash deck. The offset dedusting apparatus allows installation of a dedusting apparatus onto a diagonally oriented product discharge conduit without requiring the reconfiguration of the angle of repose for the discharge conduit. The wash deck is formed with reverse slots having deflectors raised upwardly from the top surface of the wash deck to orient the slot to direct the air flow downwardly with the flow of product and to create turbulence in the product flow to facilitate cleaning.