Very easy, very effective. Log or ask someone to log a lvl 85 char from the opposite faction who can use this perk, then make sure you are in the big raid group of the opposite faction.
Then summon everyone to the northwest or northeast tower after a few min when your owm faction has ICG and voilà, 75%+ people accept, and you win fast probably.
Done it 2 times now, both insta-wins.
* only works when you are ATTACKING