1. As far as I know for right now, Only rogues can do this.(will test and update later)
2. Poison VI = wrapping paper, nuff said ^^
3. works with wow 2.3.0 and confirmed under wowgasm
now lets get on with it then
1. First get on your rogue and go make 21 Deadly Poison VI and buy a non-unique non-stackable item to dupe (for now) I chose a shield from the plate vendor.
2. Right click the single Deadly Poison VI and Left Click the shield (item that you chose) this is essentially wrapping the shield into a gift.
3. Not really a step, just wanted to show you what your screen should look like now.
4. Now left click the stack of 20 Deadly Poison VI and drag it on top of the single poison (wrapped gift)
5. Now shift-left click the stack of 20 Deadly Poison VI (should show the gift tag now on item info) and select 1, then put that single poison in a blank bag slot.
6. Now all you do is right click the stack of 19 Wrapped Deadly Poison VI's and whala you have 19 successfully duped copies of whatever
Update ***
Ok I just found a much easier way to do this. You need a friend or 2 accounts open.
1. Make a stack of 20 Deadly Poison VI on your rogue
2. Make a warrior or something other than rogue.
3. Trade the stack of poison to your self/buddy
4. Then simply just drag the stack of 20 on the item you want to dupe.
5. Bam you got 20 duped items
Crazy simple!
** Update 2
For some reason the second time I tried the method with 2 friends, It wouldn't work simply by dragging the stack of 20 over to the item. You have to right click the stack of 20 and then left click the item you want to copy. Works fine. For some reason it's not 100% but 1 of the 2 methods will work without a doubt
credits to nirvana1979 from Dsoft