Oh I don’t think it’s doomed from the start. Like you said, it would be an arm’s race even if you just kept changing the phrase. I’m just saying this method sounds trivial to avert once they found out what the phrase is. It would probably do damage until they did. I just don’t think it would destroy it.
Squid is a man, although my wife knows pretty much everything you can possibly know about knitting and other fibre crafts. She doesn’t just knit, she spins and dies her own yarn. She has multiple spinning wheels. We used to have a loom, but it was massive, so I finally convinced her to get rid of it for space reasons.
Also, by an odd coincidence, my grandparents ran a knitwear factory in London in the 1940s and neither of them even went to university.