A lot of Diablo 3 players would recommend you to use Skorn instead o Mojo because they do not think Mojo can compete with Skorn. But Mojo is the symbol of Witch Doctor just like the Source to Wizard. Actually, one hand with Mojo can farm Monster Power 10 as well.

Cloud of Bats Build:
Spirit Walk, Souls Harvest, Firebats and Big Bad Voodoo are the top four popular skills for those who are among Paragon 50-100. Cloud of Bats do not have a large range. It needs you have a high Armor and all resistance to stand sudden blow of the enemy. Big Bad Voodoo would be great no matter if you solo or in a team. With the rune Slam Dance, you can increase attack speed, movement speed and damage all in one.

Off-hand Mojo:
Zunimassa's String of Skulls
You should search for +180 Intelligence, Critical Hit Chance 8.5%.
You can find one cheaply in the Auction House. With Zunimassa Helm, Ring, and Shoes, you could get the four set additional bonuses +130 Intelligence, +55 Resistance to All Elements, Increase Mana Regeneration by 20 per Second.

Thing of the Deep:
You can search in the AH with stats of +150 intelligence, +Vitality, Critical Hit Chance 8%.

The difference between Thing of the Deep and Zuni Mojo is the Deep has +117 Maximum Mana. And you could add vitality as well. You have a large pool to get more Mana. If you have decent DPS on the Monster you are farming, you can just choose the Deep. But if you have to low DPS, I would recommend Zuni Mojo for you.

Below is the video fighting with Monster Power 10 Uber Boss with Mojo.