 Willmann named the product using the nickname of a childhood friend, Edith "DiDi" Koster.The number 7 was chosen because Willmann considered it his lucky number since his July 16, 1925 birthdate added up to seven in various combinations.The product was sold successfully by Willmann through a network of live demonstrators at consumer shows and retail venues throughout Europe for many years and in 1987, an associate of Interwood, Tim Devlin, saw a live demonstration in Selfridges in London, and was impressed by how well the product worked.