Clean of paddy is important to get rid of impurities such as stones, weed seeds, poorly fiiled grains, soil and sometimes animal and bird feces that negatively affect the quality of milled rice. Manual winnowing is a commom practice among smallholder farmers but this practice is not efficient and robust. Destoning with motorized or manual destoners is important both for paddy destined for straight milling and parboiling as these stones may destroy the rubber rolls and the polishing seives or end up in the final product. Mechanical winnowers exist for getting rid of sand, soil, poorly filled grains, weed seeds and animal or bird feces. It is absolutely necessary to winnow paddy before straight milling. Washing, which is a step during parboiling is very effective in getting rid of sand, soil, poorly filled grains, weed seeds and animal or bird feces if properly done. If the parboiled paddy is properly dried and contamination is avoided, the rice will be clean after milling.