As far as suggesting that s/he put his alarm on the other side of the room to make him get out of bed goes, it’s been shown that being woken up abruptly (like by an alarm clock) can cause confusion upon the moment of waking and negatively effect dream recall. So it would be effective in getting him out of bed, but a hindrance as far as remembering dreams goes.
Two(ish) years ago, around the time that I first joined this site, I remember reading a post about WBTB, and it suggested preparing some math problems for yourself to do when you wake up. You do them, which wakes you up, then maybe get a glass of water or something. The problems should be simple algebra, nothing too complex.
The “drink a lot so you wake up and have to pee” solution offered by mindexplorer is an effective alternative to an alarm clock, I just hope you don’t accidentally piss in the bed
Hope I was at least a little bit helpful.