The main quicksand video companies appear to be Quicksand Visuals and Studio 588. ClubMPV also hosts videos by various companies.

I've wondered about the people who make these videos and those who sink recreationally. What the hell do you do if someone finds you? What's the risk of a bad reaction or even of the police getting called?

I've just discovered that Damsels in Distress Video Productions still does them too, although they don't update their own site any more and stick to their store.

Panzer Vore needs his own anime.