The nightingale droppings contain enzymes which are said to break down dead skin restoring complexion which has been damaged through aging or sun exposure it has been used for many centuries and fundamentally it is treated with an ultraviolet light to kill any bacteria and sanitize it it can be traced back to 11th century japan where the japanese used the guano from nightingale droppings to remove dye and stains from their kimonos they then expanded its use to beauty treatments and in