Zilch
1960s: origin uncertain; perhaps from a Mr Zilch, a character in the 1930s US humorous magazine Ballyhoo .
wiktionary
Probably from Joe Zilch, a placeholder name (compare John Doe) used by Nunnally Johnson in his column in the Brooklyn Daily Eagle from 1923; in turn from Joe Zilch, an unseen character referenced in comedian Frank Tinney's stage routine. [1] Compare the rare German surname Zilch.
etymonline
zilch (n.)
"nothing," 1957; "insignificant person," 1933, from use of Zilch as a generic comical-sounding surname for an insignificant person (especially Joe Zilch). There was a Mr. Zilch (1931), comic character in the magazine "Ballyhoo," and the use perhaps originated c. 1922 in U.S. college or theater slang. Probably a nonsense syllable, suggestive of the end of the alphabet, but Zilch is an actual German surname of Slavic origin.
The [Cadence] agency aims to have each album cover actually promote the record, on the theory that "the day of pretty, boffy, zoomy and zingy covers for the sake of zilch is no more." [Billboard, Oct. 28, 1957]
