I guess that if we had access to machines with 95% induction success rate then it would probably be very tempting to use them very often;
kind of like wanting to play an extremely good video game as often as possible, but even more amazing.

Personally I think anyone who buys a machine like that should prove that they are mentally stable.
It would probably be extremely dangerous for schizophrenic people to use lucid dreaming machines, since those people already have a twisted perpective of reality.