Don't rub too much cooking oil, it will make your hands feel sticky, and if you rub too much cooking oil, there will be a different layer of rules, which will increase the difficulty of hand dishes in the future. I have also heard some old players say that walnuts with too much cooking oil will be slightly different in color when released by hand, so I think walnuts are best placed on hand. If you are located in a dry area in the north, it is recommended to apply some walnut oil or Johnson & Johnson baby oil on the surface of walnuts, put them in a sealed bag and store them in a cool and dark place, so that you don't need any oil to play.