Those videos where popular pornstars read Erotic Literature while masturbating under the table. Or those videos where it's just a single woman on a pitch black screen masturbating.
It's a weird fetish that nobody else in the world has other than them. There is no name for it, no porn of it, and nobody can adequately explain it. It involves 19-21 year old women, one of those old-timey hard diving suits, a literal dumpster full of piss.