It's worked for me, but not right after initially going to bed. It works best for most people after 5 hours of sleep. Doing right when you first go sleep is difficult, being sleep deprived on top of that would make even harder.
Have you ever had a dream, Neo, that you were so sure was real? What if you were unable to wake from that dream? How would you know the difference between the dream world and the real world? Morpheus