The ruse of using the Hindu shuffle to display apparent duplicate cards in the deck was included in Jack Chanin's “Seven in One” card routine from Further Adventures of the Seven in One, 1938, p. 11. Advertisements for Chanin's booklet began appearing in April of 1938 (see The Linking Ring, Vol. 28 No. 2, Apr. 1938, p. 142). The following month, Harris Solomon suggested the same ploy in his trick “Nomolos” in The Jinx, No. 44, May 1938, pp. 301 & 303.

Also see Flushtration Count.