I want to finish Master of Strand of the Ancients before it goes away, and I don't see how it is possible to win the game without losing any demos. Even the worst teams I've faced have had someone willing to kill a demo in 3 hits. With all the immunities and spell reflects in the game, you can't lock anyone out of doing what they want for long. And even if you find a team that can guard both the demos on the docks for 10 minutes, winning the game using only bombs seems unfeasible. Any amount of damage including dots will cancel the cast, making it possible for the shadow priests and warlocks on the enemy team to spin the door even while they are dead.
Is there a good strategy for earning this achievement?