Ah! Now that does surprise me, that it's commonplace in America. From the feel of it, I'd have put it down as a Brit-ism, which was most definitely localised. A plausible explanation for it, so I thought, was that it came from a child's mispronunciation of "sick" (I can just hear "Ugh, that makes me feel so squick"!) which then spread from family to family within a relatively small area.
But if it's widespread, perhaps it was a deliberate portmanteau of "sick" and "quick" because the offending matter speedily causes disgust.
I've never heard it used, but I'm not a watcher of TV or listener to radio, so lots of new words pass me by, and I have to wait for them to gain enough acceptance to emerge in print, where it's not yet appeared in anything I read.
The mystery deepens!
