Well, no, I haven't. Time doesn't really matter much to me, because most of the time I'm too busy daydreaming and preoccupied with other thoughts to even care.
However, the theory behind it is simple. It works the same way that building any other skill works, and it's even something that the horrible education system does somewhat correctly. Very simple idea - practice becoming accurate at one thing or another, and with time your brain automatically gets better at it.
It's just the same as practicing math, or Chess, or even intuition. As they say in the Sedona Method, "'intuition is only correct 100% of the time,' but it's emotional interference that gets involved." If you can find a way to let go of fearing your intuition being wrong, you can certainly improve it, as well as any other skill, once you remove fear, worry, or sometimes even concern.
-youngprer
geocities.com/doc5587
pub117.ezboard.com/btheworldofyoungprer