na-poo, whonky

[Arnold Zwicky]

the OED has earlier cites for "napoo", but this one from 1921
(Herbert Jenkins, _Malcolm Sage, Detective_.  George A. Doran
Co., NY - citation contributed to me by a friend) is fairly
entertaining:

  "...when I found the bloomin' engines had gone whonky, then -"

  "Found the engines had gone what?" enquired Mr. Walters.

  "Whonky, dud, na-poo," explained Richards illuminatingly,
 whilst Mr. Walters gazed at him icily.

arnold (zwicky at csli.stanford.edu), with thanks
  to ann burlingham of perry, new york