[quaddo]

Thanks for clarifying "hair shirt". I'd seen you mention it at least 3 times previously in comments, and was trying to unpack it without doing a search. Thoughts such as "they're quite fond of stylish hair and t-shirts?" and "they like t-shirts with hair designs?". I think my worst take was "they fetishize wearing someone else's chest hair, like a shirt?"

Popped onto DDG just now, and the explains right there. Also "cilice" within the first few links.

[quaddo]

I just scrolled a little further in the DDG results to see a hit on Amazon.

After my unexpected laughter, I had to click. The first 2 hits align with my prior misunderstanding - cue more laughter. One is a t-shirt with a graphic of a very hairy chest/abdomen, the other has the likeness of Chewbacca with "Messy hair / don't care".

No need for anyone else to see for yourselves; saved you a click.