Most people don't own them. When you want to visit, you go to a place where you rent a room. These rooms aren't attached to nightclubs because they need way too much space behind the scenes, and all of the ambient effects from the club would affect the way that the rooms work. But they tend to be in the same districts...they're often pretty far underground.
Some people become addicted... and agree to become research subjects in return for allowing their brains to be used for information mining. (In reality, they're also looking into your brainwaves to determine whether or not someone might be a psychic... and then taking some of your brainwave information as well and putting them into a database along with the measured blue hell or red hell frequencies.)
But the strangers... out of sight, out of mind. It would seem kind of wrong to have the stranger in the same room as the kaleido-machine. You would want to believe that it couldn't be tampered with. You would want to believe that you would not be able to stick a knife into it and give yourself a seizure, nor that anyone else could come inside and do that to you.
Despite the chaos, there was some kind of shape coming together, and events were happening were at a larger and larger scale. There were people who were doing all kinds of sick research...