> hitting one's jaw with a hammer was a real phenomenon

It isn't? I thought the main notoriety of https://en.wikipedia.org/wiki/Clavicular_(influencer) was his promotion of "bonesmashing"

Ah, but, perhaps none of it's real: https://en.wikipedia.org/wiki/Looksmaxxing

> More dubiously, a practice known as bonesmashing, which refers to the act of hitting one's face against objects such as a hammer in order to create a "chiselled look", is often described when discussing looksmaxxing. This practice is considered an inside joke and is rarely done. Sources label it as misinformation.[23][24][25]

There appears to be a number of claims that people have done this, but no hard proof. Very much like an urban legend.