Use eggshells. Prepare some egg shells, preferably more, then crush them, put them in oil bottles and barrels, add hot water and shake them vigorously. After a few minutes, the oil inside will come down and wash them again.

Method 2:

Prepare some fine sand and baking soda, put them into oil bottles and oil drums at the same time, then add hot water, which is also shaken, and finally rinse it off.