Well, I've only tried this once on a woman 10-15yrs my senior. May try it in day game, but I think it may be better in mid-game to see if a HB is into alternate thought type stuff (esp. if you are as well, as I am myself). This is how it went.

OM: Hey, have you ever had a dream where you're flying?
Her: No
OM: Ok, have you ever had a dream where you're falling?
Her: Yes!
OM: Ok, was the falling just before you woke up?
Her: Yes.
OM: Hmm I see. Do you want to know why that is?
Her: Yeah ok
OM: It's cos during certain states of sleep, you actually leave your body. The memory of flying/falling is a recollection of this. The falling is you racing back to your body cos you have to wake up
Her: Oh, ok (kinda non-plussed)
OM: Blah blah who r u here with?
Her: blah
etc

She later mentioned it wasn't a great chat-up line, but like I said, on the right girl it might flick a switch, who knows.

PS: That flying/falling/out-of-body stuff is actually true.

It will work on anyone who believes in ghosts. Good job!