Hi people,
I got a mangos/Trinity new duping method with guild bank, but I won't give it happily to people, I just want people to think a bit so I'll just give you some clues how to do it and if you got or you are near to get it just PM me and I'll help you or compare your method with mine.
so the clues are:
you need WPE and full acces to guild bank...
you need to stack 19 item together (not the item you want to dupe...i can be some cloth,wood,..etc)
So...now...you have a stack of 19 item (last item gonna be for the item you want to dupe)
you have to find how to put the item you want to dupe in the stack (it gonna make a stack of 20 item of the item duped)
i only tested with guild bank...maybe you can do it with your bank too