Anecdotal, but I have a 100% hit ratio at Berghain and have never done any kind of prep work. Most of the times bh was not even part of the plan and we would just show up there, sometimes still with the backpack from work, laptops and all. Maybe two or three of us, sometimes on my own. I think it sucks that so many people are rejected at the door, but the approach clearly works once you get inside and feel the vibe.

I was rejected at Kater Blau once though, for who knows what reason. It's the way it works, if you get bumped you can get angry at the system or just forget your ego and go elsewhere and enjoy the night.