Cure for baldness
Hair popping was developed as a claimed cure for baldness around the 1950s. It involved pulling on the scalp until it made a popping sound. And yes, it was apparently quite painful.
Some details from Baldness: A Social History by Kerry Segrave. Trained dietician and cosmetologist Rita Hartinger was the foremost practitioner of the "hair popping" technique of hair preservation and regrowth; she was working out of New York City in 1968.
Eight years earlier she had learned the trade from its originator, hairdresser Marsha Lewis, since retired.
Hartinger called herself a "professional hair popper", believing her method of scalp stimulation helped her customers keep whatever hair they had and perhaps sprout a new crop.
"I make the hairs healthy ... When you lift up the scalp from the bone structure by popping, it stimulates circulation and nourishes the tissue. Then the hair is strengthened, and it is less likely to fall out," she said.
A journalist who watched Rita in action reported that each tug on the scalp did indeed produce a "pop", and he described the sound further by writing it was "as if a kernel of popcorn had exploded on his head".
Hair popping, as a cure for baldness, fell out of fashion.
But recently it's re-emerged as a fad on TikTok. Though it's now being called "scalp popping". (Via Weird News)