Home Product Cleaning & Conditioning Cast Iron Scourer CAST IRON SCOURER Cast Iron Surface Scouring. Wheat kernels rub against cast iron surfaces, creating friction that gently cleans the outer grain surface. Removal of Adhering Impurities. Dislodges dust, dirt, soil and fine husk particles that cling to the wheat kernels. Separate Impurity Discharge. Loosened surface materials are separated and discharged from the machine. Cleaned Wheat to the Next Stage. The scoured wheat leaves the machine for further processing.