Just a heads up for anyone using the script for this one: Because the strategy has you bringing in your second random pet, you'll need to manually run the fight for the second pet. When the second pet dies, the script will take back over. (Unless of course your second pet is an emerald proto-whelp or a dream whelpling!)
Make sure the Zandalari Ankle render is P/S breed. That's crucially important here. If you use a P/P breed, it's the same speed as the Ectoplasm (276), and therefore the Ectoplasm has a 50/50 chance of going first. Being faster slightly reduces your damage from P/P, but makes sure you get that last hit in.
Note that using an S/S or a P/B Anklerender are even worse than P/P, because the S/S is too weak to be effective, and the extra speed over a P/S is completely wasted, and P/B has the same speed as P/P, i.e. 276, or same speed as the Ectoplasm, and is weaker in its attacks.
I used the strat posted with a P/B Zandalari Anklerender. My Anklerender died to the Ectoplasm in Round 2 due to bad RNG. The EPW was able to finish the fight np. Just wanted to note that it is possible to not kill Ecto with P/B.