Do you think an attitude of gratitude is a great tool for destroying the Ego?

No one reminds the other; they refine. Do we smash a rough diamond to make it shine? No master cutter ever destroys the stone. You destroy the value.
The question is: renouncing as an act or as a result of God realization?
Which comes first, a chicken or an egg?
I concur with Priyanka: who are we to shape ourselves?
Even if we do try, it will still be an act performed by the Ego (wanting something in exchange – God himself).
So, pursue God realization, and when that happens, gratitude arises from within.
Anything that comes while the Ego is alive is worth two cents.