I found out these quest mobs have pretty spawnrate and low HP. They drops some grey crap to be sold to vendors, but also Motes of Harmony. Even some green and blue items dropped in that while when i tested it..
Step 1: do chain quest to Zhu's Despair - Quest - World of Warcraft (its just 3 quick quests)
Step 2: have lot of space in ur bags, didnt added vendor because when you go too far away you´ll get out of the phase and have to abanndon & retake the quest.
Step 3: Grind your arse outta them!