You have to run it for several hours, hell, even leave it overnight if need be. Even then, it only works 1/2 the time. I had a dead pixel on my old screen right down the middle, it was huge and PINK! My solution: get a new screen.
I know of several people who used a cleaning cloth and simply massaged the screen until the pixel became unstuck. It doesn't work all of the time (probably about as often as the other suggestions), but it's worth a try.