Uguisu no fun is a face cream that was once used by geisha and Kabuki actors in Japan, but has recently become more famous as a spa treatment and exfoliant. The secret ingredient? Nightingale poop.
Smearing bird droppings on your face to look good may seem counterintuitive, but according to the Shizuka New York Day Spa Web site, geisha realized that nightingale droppings could be used not only to remove makeup, but to "brighten, heal and retexturize" due to the presence of guanine, which gives skin a "pearly luster" [source: Shizuka]. Though guanine occurs in guano from other birds and bats, as well as plant extracts, the nightingale's song gives it a romantic air that adds a touch of class you wouldn't get with, say, pigeons.
Although it's one of the less expensive skin care products on our list, it's not cheap. Uguisu no fun facials at the Shizuka New York Day Spa are $180 for a 60-minute session. If you're in the mood for independently mixing your own bird-dropping facials, you can pick up an ounce of uguisu no fun powder for a cool $36 [source: Ten Thousand Waves].