I don't really think you'll have to put the watch next to you when you sleep so that this method will work. I think the fact that you're RCing every hour helps a lot in increasing your awareness. Since after a while RCing every hour will become more of a habit, you'll probably end up naturally RCing in dreams more often and getting more lucid dreams.
I was actually thinking about something like this about two days ago, but thought I would want something better than a hand watch. These watches have very soft beeps it's very easy to miss them.