So I found there were a couple of ways to farm instances by making npc's do all the work.
- This works in Hellfire Ramparts: Aggro Mobs on the top tier of the instance and they run back through the instance pulling everything. You can do this on multiple characters on the SAME account and farm much faster than you would be able to on one.
- In Shadow Labs you can send a pet/minion to kill 2nd boss Blackheart Inciter and the pet will return through the instance with a huge trash pack in tow. Again you can do this with multiple characters.
There's a video of this here: