Masturbation sock. Guy slides sock over his cock and strokes into the sock. Easy clean-up. Sock-pussy is also used as humiliation when a girl instructs a guy to go get a sock-pussy, because he's not getting real pussy.
Nicole told the idiot to go get a sock-pussy and stroke off, because there was no way he was going to be getting any real pussy.
Melissa has been porked so many times that she has tube sock pussy. Hell, she's so loose that she couldn't use a roll of wall insulation for a tampon. It'd just fall right back out.
An item that is used in jail or prison. Take an ordinary sock, insert a plastic baggy into the sock, fill the baggy with vaseline, then use it to whack the shit out of your pud. When thru, discard the whole thing. Told to me by an ex-jailbird.