As if you needed another reason to get the Praise The Light emote, a fireteam of Sunsingers (consisting of Buz Lightbeeer, TheGreatNike, Gladd, rowan, Snerv, and ITI) has defeated the final Wrath of the Machine encounter without firing a single shot (other than the required Cannon shots).
Gladd has a detailed guide on his Reddit post, but I think I'll settle with watching their incredible footage of the event.