I've never done it myself but appearently:
All 6 go into the BC, however one must stay within the CS and never come out.
4 of the members logout immediately.
the 5th person pulls the Mammets to the person still in the BC and dies.
The Mammets agro the person within the CS and because of that, he takes ZERO damage. The others log back in and the one who died gets back up.
Wait for weakness to wear and pull the Mammets off the dude in the CS one by one.
The Player in the CS will then come out of the CS at the last fight and they all win.
Errr, that is completely unrelated to the extent of this glitch being mentioned here.
Keywords: Item duplication
romperstomper: oh ok lol