To me, a random glory hole sounds like it could/would be the hottest thing ever, but it's not very realistic.
I don't know how anyone can ****** themselves to a disease or infection from a total stranger, but more power to those that can.
With that said, I do think a glory hole could indeed work in a controlled environment. For instance if a husband had enough trustworthy friends that would participate, and a willing wife, he could make his own glory hole to use. Perhaps one custom-built at home or one that's portable enough to take to a hotel or other location.