Plain water wasn't good enough for Cleopatra, who preferred to bathe in asses' milk.
There's something fishy here: Catherine Zeta Jones uses caviar to give her hair its noteworthy shine
Catherine Zeta-Jones, it would seem, has a similar attitude to shampoo andconditioner.
While most of us have to make do with a handful of fragrant soapy foam, the Welsh actress smears on truffles and caviar.
At ?200 a time, just for the fish eggs, looking good does not come cheap.
But she credits the gourmet delights for giving her long brown tresses an unbeatable shine.
"Catherine discovered the caviar treatment last summer and was astounded by the difference it made to her hair," said a source.
"She has an incredibly rich and vibrant natural hair color but the creamy, almost oily nature of caviar really brings this out, making the color even richer and making it so much more glossy.
"The eggs are packed with omega-3 fatty acids necessary for the formation of structural proteins. It is these proteins that repair dry and damaged hair and smooth over anysplit ends."
Miss Zeta-Jones's hair is washed with a truffle-based shampoo, then smeared with the caviar and which is combed through and left to set.
Unlike many fad treatments, caviar is actually proven to work as a conditioning therapy. The essential fatty acids it contains produce collagen and keratin, two proteins vital for the appearance of sleek hair.
In 2005, the former Darling Buds Of May star was voted the celebrity with the "best dressed" hair in a nationwide survey by Sunsilk and London's City University.