What's the etymology of the word "zilch"?

Solution 1:

This website says

Robert Hendrickson says “zilch” goes back to the 1920s when the name “Joe Zilch” was used to mean “a good for nothing college boy” – someone who was a waste of space.

Looking through Google books, “Joe Zilch” certainly seems to have been used in that way. It would be quite a coincidence if these two usages of "zilch" were unrelated. And unless someone can find an early attestation for "zilch" meaning "nothing", it would appear that "Joe Zilch" came first.

From 1925:

Such men as Joe Zilch, Joe Mulch, Joe Collitch, Samuel Hall, and Others have been members of this Paternity. ... Said to be Very Exclusive, absolutely refusing to take in others than Protestants, Catholics, Jews, Negroes, Mohamadens, S. C. A's, Westerners, and Round Table boys.

Solution 2:

Stumbled upon the post and decided to post quick update from 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]

http://www.etymonline.com/index.php?term=zilch

Solution 3:

Maybe it was from Yiddish-German, from the Slavic side. I think it may have originated from that useless cure all, zhelch, which is Slavic for bile.