20 minutes. Mud moxibustion ointment is a dressing for eliminating dampness and preventing palace cold. It can only be used after heating to achieve the expected effect. Convenient and quick use, good effect. The mud moxibustion ointment can be heated by microwave oven, steamer and air fryer, in which the air fryer is heated at 120 degrees for 20 minutes. Clay moxibustion ointment can be purchased in various pharmacies and online sales platforms.