Works on all maps, and all you have to do is get a friend to kill theirself with their grenade in a corner. Then stand in front of them and crouch. No zombie will be able to hit you if you do it right. Let's keep this one quiet guys, this is a great glitch. :shh::shh::shh:
Tried this last night on Shangri La and Five but had no luck. Is it patched or am I just doing it wrong. We had the host go down and then I revived him. He then stood up and I stayed crouched down. the zombies then ran over, laughed and said "Here have a zombie back hand", hit us and we died. Would be awesome if it did work but as yet I can't do it