The Wallbreach glitch is similar to the Underground glitch, but this time, it's located under the bridge in the red circle indicated on the map above. All you need to do is go up the grassy stairs under the bridge, go to the top by the wall, and jump inside the breach there.
Again, you will be invisible to all other players, and you can shoot them without getting detected. However, some players have reported that it is possible to kill anybody hiding under the stairs using grenades.
But no matter how hard you try, even if you decide to use this location, you will eventually not be able to climb back up. This means that you will be trapped and the storm will kill you at some point anyway.