First go into the AH in the Valley of Strength and blink into the boxes that are in the far right corner of the AH. Turn around 180degree's and blink back (you might need to do this a few times) and there you go, you are under the horde AH, you cant see the people in the AH but you can see everyone else as the AH becomes invisable. You cannot get targeted while under there (but also you cant target others). so i guess the plan is to jump out pwn blink back in and hide
I hope some other people might be able to find ways to make this more useful? Let me know
Have fun pwning my horde brothers :P