John Merwin on the Mickey Finn

John Merwin asks why the Mickey Finn persists as a popular pattern when other streamers work better. Is it in the derivation of the name? “In 1936, Gregory Clark of the Toronto Star re-christened it the Mickey Finn, in supposed honor of film star Rudolph Valentino–who was allegedly killed by mickey finns (meaning drugs, not flies) that were slipped into his cocktails.”