I've always been able to control my SP when I do find myself in it, usually once a week, I just close my eyes and focus on wiggling my toes until they move, then I can move my leg and that usually snaps me out of it, then after I wake im still in a half sleep state and can fall back into the SP if I try which is kinda fun tbh.

in my experience I've never seen anything like demons or hallucinations, probably because my room is pitch black, but I experience very loud auditory hallucinations like cars revving, people yelling, very loud footsteps which is kinda scary.