Potions suck. But i may have found a semi-decent one.

When I'm MT as Warrior and use Unchained+Berserk for increased aggro/damage, i get the Pacification effect after berserk wear off and i cant do any GCD skill.

When that happens, I use a Potent Poisoning Potion HQ.
It works even on 2nd coil bosses. It's a small DoT that lasts only 15 seconds, but it's better than doing nothing for 5 seconds.