Once again, this is a hunter only trick! (my appologies)
Also, please note this was done at level 60.
Anyway, over the last few days I've used it to farm over 500 of both types of cloth, and make quite a hefty profit. (It's the only thing holding the war effort back on my server.)
Anyway, when you zone in, there are a series of different rooms.
Tunnel -> Ogre Boss.
Tunnel -> Goblin Room.
Tunnel -> Another Goblin Room.
It is best to stop at the second "Goblin Room" as it takes more time to clear.
The Steps:
Lay down an Explosive Trap
Cast "Eyes of the Beast" (The timer that comes up is also the same as your trap -- so you can use that to know when your trap is going to expire.)
Anyway, run around the entire first tunnel, aggroing every single mob.
All but a few are "Defias Miners", who are non-elite.
With Eyes of the Beast still on, stop a few yards in-front of your trap. Wait for all the mobs to be grouped up onto of your pet. Walk onto your trap. The explosive trap will kill them all. The initial blow will do away with 80% of their health, and the tick will finish them off very quickly. Off each 'tunnel' alone you can get a stack or more of each. Each tunnel takes about a minute and a half to clear.
This isn't an exploit, just more of an easy farming trick!
Have fun!