I've slipped into it before after a lot of practice. It's a pretty interesting experience. You can move around to break it but It's trippy, there's about a very long 15 second delay from you saying "dammit arm, move" before it actually does anything. Every time I think I'm about to fall asleep when attempting it, it creeps me out because my eyes just open and I can't close them. I haven't seen anyone at the foot of my bed but usually out of my peripheral I see shit that freaks me out.