Hollywood star Catherine Zeta-Jones has a unique way to stay beautiful - she spends $400 (GBP200)-a-time on caviar shampoo. The Beluga caviar treatment may carry a hair-raising price but it has been credited with giving the actress' hair an unbeatable shine. It is flown from Iran five days before her visit to a beauty salon in London, U.K. A source at the salon tells British newspaper the Daily Mail, "Catherine discovered the caviar treatment last summer and was astounded by the difference it made to her hair."