Savon de Marseille soap flakes are made from olive oil. For best results, dissolve 1/2 cup of soap flakes in 1 gallon of warm water. Recommended for hand-washing of delicate fabrics such as wool, cashmere, silk, linen, flannel, chiffon, cotton, lace and down. Soap flakes can also be used with washing machines. Pour 1/2 cup of soap flakes directly into the machine and choose a cycle that uses at least 86 F (30 degrees Celcius) water.