The invention relates to a method for producing acetic acid from ethane and oxygen on a fixed bed catalyst, characterized in that a reactor cascade with an oxygen feed between the reactor levels is used. The center region surface is defined peripherally by the horseshoe-shape surface and extends from a heel front edge towards a heel rear edge. Each of the local-area line-shaped protrusions reflects the entered light so that a component of the entered light which is orthogonal to the first direction is weakened. The substantially wet, cleansing andor moisturizing agent is then allowed to dry into a generally dry, water-soluble, cleansing andor moisturizing agent at the core of the luffah.