Laundry Detergent Powder Recipe - Food.com- how to make washing powder washing powders recipe fabric washing powder ,ounces bath soap, grated into flakes (Approx. a half a bar of soap, fels naptha works great. Also Zote or Octagon)Laundry Detergent Powder Recipe - Food.comNov 17, 2003·ounces bath soap, grated into flakes (Approx. a half a bar of soap, fels naptha works great. Also Zote or Octagon)