The no-poo (no shampoo) movement is very real and definitely works for many people (dependant on hair type and oil secretions). Basically, once you stop washing away your natural oils daily, the production normalizes and then a regular rinse with water and occasionally something like diluted soap, lemon juice or apple cider vinegar.
I’ve met them, I was one, I know them. You wouldn’t know unless they told you.
When cocaine usage first exploded, it was almost entirely in “laborers, youths, black people, and the urban underworld”. Most of the early history of its usage is associated with non-whites and lower class peoples. Making it illegal worked for a long time until the cocaine boom happened and then it became popular with disco and rock, but again, still mostly used by non-whites. It wasn’t until crack became a thing that the racial divide became more clear - rich whites got the clean cocaine, everyone else got addicted to crack.
https://www.degruyter.com/document/doi/10.12987/9780300255874/html
The switch to being heavily used by the rich white class is a “relatively” recent development.