A method is provided for cleaning an exterior surface that is stained as a result of biological growth of an organism, such as algae, lichen, or moss. Method for manufacturing a product comprising the biodegradable support having a bacterial mixture comprised of Bacillus species. A series of similar bows is pivotally attached at or toward the front of the chair. The winding member is mechanically connected to the driving device, the driving device drives the winding member to wind or unwind the rope, and the sidewall is closed or opened according to the rotation direction of the winding member.