Abstract: A barrel for use in treating workpieces, such as cleaning, scouring, deburring, etc., with abrasive blasting particles, high pressure fluid jets, etc. The barrel is intended to be rotated and includes a novel spiral flight which pushed workpieces through the barrel, a novel arrangement of drain holes for voiding the barrel of debris such as blast particles, flashings, cleaning fluid, etc., and includes novel turning cleats which cause workpieces to turn over within the barrel to expose various portions thereof to a blast stream of particles or fluid.