mint gum. pure and simple. keep it on your tongue while you sleep. there's no way to choke from it (at least...low risk, its gum kay?) and it works really well. first time i tried it i got 2 lucids in one night.
got the idea from a friend who doesn't use forums..but his grandfather studies lucid dreaming.

different brands work, and some don't...i wish i remember the brand i used.