I've been involved with computer networking since approximately 1982, and I've never once heard someone use "squirts" outside talking about Zunes. I don't doubt that it was jargon inside very specific niches, but it has never been common elsewhere.
Before the Ballmer/Zune use of the term I remember my father talking about data being squirted to A2A missiles (he was military) prior to launch, so perhaps that is one of the niches.
I take that back. An old issue of Wired had a jargon watch mention of “squirt the bird” as bouncing something off a satellite, which I remembered only because they misspelled it and I wondered what “quirt” meant.
So yeah, maybe that’s a military or adjacent thing.
