How do you get darkrai with glitch?

Theres a way to get Darkrai without event and action replay in U.S version. First bring some pokeballs. (recommended ultra, dusk, timer)

First go to full moon island. Then theres a glitch were you can walk through one of the trees. Then you will walk through the trees. Surf on the water and keep going right. You will end up near new moon island. Go down and get back on land. Go and Catch Darkrai! What tree