Proving Yourself: Gold Damage

I'm finding this REALLY hard on a warlock.
Not enough stuns, slows and interrupts plus having to stand still while casting makes the banana tosser really tough to take down even at iLvl 685.
Any ideas?

Finally got this done.... again. You know I got this done in Pandaria, not sure why the achievement points haven't carried over seeing as how it's the exact same set of fights... Anyways, my tips:

Did it as ilvl650 Survival Hunter.

1) Grab the tasty food the vendor sells, eat up. Every little bit helps. You don't need the healthstones, so don't bother.

2) Use your Oralius' Whispering Crystal and get your stats +200 for an hour or a flask/potion that does the same thing or more.

3) Mass spam the tab key and your most powerful insta-attack before a round begins, usually you can take out a mob before the healer has a chance to throw a heal onto it.

4) Always kill the healer as soon as possible, silencing its heals, and when there is a secondary heal CC it until you're ready to attack it.

5) You can use the first DPS buff on whatever fight seems toughest to get past, but SAVE the final DPS buff for the final boss. I believe it pops 2 or 3 rounds before the final fight.

6) Being Ranged, I almost always attacked the banana monkeys last, being a hunter I could care less if it went to the outskirts, being a melee class I couldn't imagine having to run after it when there's only 5 seconds left.

7) When on the shield bosses, when there is nothing else to fight DPS it down anyways. Always keep your black arrow on it, even when the shield is up. Every little bit helps. Save your most powerful attacks as soon as the shield is down.

8) On the final boss, kill the small add first, then the exploding add, all while keeping damage on the boss even when the shield is up, when the shield goes down grab the DPS buff you saved and go nuts on the boss using your powerful attacks that you saved earlier. An exploding mob shows up, don't attack it until you've got every ounce of damage on the boss you can before attacking the exploding mob.

9) Don't neglect your explosive trap for any of these fights, especially the final boss. Every little bit of damage helps.

10) Achievement Completed.

I just did this on my enhancement shaman. It is quite challenging and fun.

Enhancement Shaman Guide:

The important part is managing your cooldowns and using Magma Totem when you can deal damage to two or more mobs, and Searing Totem when you are fighting one mob. Interrupt healers and interrupt Amber-weavers when there are no healers around.

TL;DR:
Wave 1: No CD. Middle guy first.
Wave 2: No CD. Kill Banana-tosser first.
Wave 3: No CD. Hex healer. Kill banana tosser first.
Wave 4: Ascendance. Kill banana-tosser. Interrupt healer.
Wave 5: Liquid Magma.
Wave 6: Liquid Magma, spread flame shock. Kill healer. Interrupt healer.
Wave 7: Hex healer. Elemental mastery, Liquid Magma. Kill banana-thrower.
Wave 8: Kill adds. Earth Elemental, Feral spirit and Liquid Magma when shield is down.
Wave 9: Hex healer. Kill adds. Damage boost, Elemental mastery, Ascendance.
Wave 10: Kill adds. Heroism/Bloodlust, Liquid Magma, Fire Elemental, Feral Spirit. gz!

Details:

Wave 1:
No need to use any cooldowns, attack the guy in the middle and spread flame shock. Pick them off one by one.

Wave 2:
Kill the banana-tosser (dodge the ambers). Kill the amber-weaver. No cooldowns.

Wave 3:
Hex the Mystic (healer), kill the banana-tosser, kill the amber-weaver. No cooldowns.

Wave 4:
Attack the banana-thrower. Interrupt the healer when he starts healing. Kill the banana-thrower and then the healer. Use Ascendance to kill the healer.

Wave 5:
Magma Totem in the middle and start off with Liquid Magma. Should be easy enough to kill without any more cooldowns.

Wave 6:
Magma Totem in the middle, spread flame shock in the middle group. Attack one of the healers and use Liquid Magma. Use Fire Nova when you can. After you have taken down the first healer, interrupt the second and kill him. Deal with the remaining adds (should be on very low HP or dead).

Wave 7:
Hex Healer. Attack the banana-thrower and use Elemental Mastery. Use liquid magma when the banana-thrower gets low on HP. Attack and interrupt healer. Deal with the rest.

Wave 8:
Don't use cooldowns quite yet, deal with the adds first (dodge the ambers). Use Earth Elemental, Feral spirit and Liquid Magma when he drops his shield.

Wave 9:
Hex the healer, deal with the annoying monkey. Just before the big guy drops his shield pick up the damage boost. When the big bad guy drops his shield use liquid magma, Elemental mastery, and Ascendance.

Wave 10:
Deal with adds. Pick up damage boost after you kill the exploding ghost. Heroism/Bloodlust, liquid magma and fire elemental. Use feral spirit when its off CD and he has dropped his shield. You should be able to kill him before the shield gets up a second time. Kill the exploding ghost. Congratulations!

Talents used:
15: Astral Shift, 30: Windwalk Totem, 45: Call of the Elements, 60: Elemental Mastery, 75: Rushing Streams, 90: Primal Elementalist, 100: Liquid Magma

Stats:
2604 agi, 13.36% haste, 30.76% master (ilevel 592).

Stats at proving grounds:
2734 agi, 22.71% crit, 12.26% haste, 30.76% mastery.

Keep in mind that this is just what worked for me, depending on your talents and gear something else might work better. Please let me know if you have any suggestions.