While the buffs you get from the bags are not the greatest, they're good to use for instances / scenarios since they are free. You usually get cash, motes and sometimes herbs / minerals - so I suggest using it every cooldown just to farm stuff.
To avoid having to keep track of Wikky, do what I do. Find a place where there are 50 easily killed mobs where you go after activating. My favorite spot is Paoquan Hollow (north western part of Valley of the Four Winds), the flies go down easy and there are plenty around.