The charm upgrade potion says "Drinking this potion temporarily increases offensive charm trigger chances except Cripple."
So it clearly applies to Curse, Divine Wrath, enflame, Freeze, Poison, Wound, and Zap.
Does that mean the potion only applies to charms that I have unlocked?
Would the potion only impact the creature I have assigned to the charm?
Since the charm normally has 5% of triggering, does that mean it has an additional 0.25% of triggering with the potion?