News of it has only just reached the West, but bird poo facials have been big in Japan for several years. It's not just any old bird poo: the pricey stuff is the excrement of nightingales from the island of Kyushu; it is said to have an enzyme that breaks down all the dead skin on the user's epidermis. Just ask Victoria Beckham, whose dewy complexion is reportedly down to the songbird's guano—dried, mixed with rice bran and faeces and applied as a face mask in selected high-end spas.