Breaking news (to me): blick is an actual word of English.
Yup, I fully admit it. Until very recently, I never actually picked up a single dictionary and checked to see whether blick was in it. I just recall the feeling of my own first exposure1 to the example as being so effective that it never even occurred to me to double-check it. But now I see that Dictionary.com has a definition, as does the OED (if you have access). Prolly others, too, but why keep checking?
Of course, I recognize whether its actually found in any dictionary is not the relevant criterion for the example’s effectiveness. Jim Huang articulates the relevant criterion perfectly in these lecture notes (emphasis added):
(2) English phonotactics: brick, blick, bnick, sdpick.
These examples show […] whether a given sound sequence is a possible sequence in English even if you have never encountered the sequence before.
But I have to also admit to having gotten personally tired of the example by, oh, I don’t know, like the umpteenth time I taught it. So beginning some time ago, whenever I would introduce the brick, blick, bnick triad, I would very soon thereafter tell my class that both phonotactically possible but allegedly nonexistent blick and phonotactically impossible and supposedly nonexistent bnick have by sheer force of repeated use become words of my vocabulary, with the respective meanings “string of sounds that some sloppy linguistics teachers use to demonstrate the notion of a phonotactically (im)possible but nonexistent word of English.”2
To which I have to add from now on, in the case of blick at least: “Incorrectly, as it happens.”
1 Though nothing else about the exposure rings a bell. Was it in a class? Did I read it somewhere, or hear about it at a talk? No clue.
2 This definition abbreviates two definitions, applied anti-disjunctively.
[ Hat-tip to Andrew Strabone. ]