First, wipe it with a scouring pad dipped in toothpaste.
Secondly, dissolve the incense ash in water and wipe it with scouring pad.
Third, cut the pineapple skin open and boil it in water, then put the bottom of the pot with oil stains into the boiling water with pineapple skin, and the black at the bottom of the pot will disappear after a while.
Fourth, wipe the alkaline surface with water.
Among the four methods, alkali powder (the fourth method) and incense ash (the second method) have the best effect, because the main components of the dirt at the bottom of the pot are acidic, while alkali powder and incense ash are both alkaline, which will be neutralized when they touch each other.
And the best way is to use an induction cooker.