Today I obtained the item Helpful Wikky's Whistle - Item - World of Warcraft, it drops from Major Nanners - NPC - World of Warcraft . This item will summon Helpful Wikky - Spell - World of Warcraft . After what i've counted to aproximately 50 mobkills Wikky will come up to you and you'll be able to talk to him and recieve Bag of Helpful Things - Item - World of Warcraft . This bag always (as far as i've seen) contain a few motes and some flasks/pots. Check the item for the full list of loot.
You probably think that 50 mobs is alot, but I went to "Paoquan Hollow" in "Valley of the four winds" (Roughly at 17, 35) and farmed the Zijin Hollowfly - NPC - World of Warcraft , since they have so low health aprox 21.5k they die more or less instantly.
1. Get the item from Major Nanner
2. Use it when you're at your farming place
3. Kill mobs, when Wikky spawns again talk to him to get the bag.
5. Repeat step 2 and 3
EDIT: I might say that this is just 1 time per 2 hours, even so it's an extremely easy way to get 2-3 harmony and perhaps a few valuable crafting items.