Obviously in guides because it isn't really an exploit.
Had previously cleared 6/7 prior to doing this so the corehounds and molten lords weren't respawning. Pretty much everything left in the instance at that point is snareable. If your going to kite around in circles you will need to spec Concussive barrage and pref. Bombardment. If using the kill one and FD method, any spec will do. So far the Hell Hounds have dropped the most epics for me, so they are probably your best bet. Made a quick video showing it a bit better.
YouTube - ‪Solo Firelands Trash‬‏
I can't see them nerfing it because soloing them is quite out of the ordinary. Have fun.