Once you get the hang of Brayflox and don't get a crappy group it's really simple to do. MP potion can help i used to like popping one after i drop 10-15% MP so i know it will be off CD if the fight drags on and i need a late MP boost. The rest just hope for good freecure procs. If it's not getting too out of control you can let a couple of poison stacks hit the Tank before removing it the poison alone won't kill them remember SCH does this without being able to clense and you have really good single target heals plus a proc for a Cure II that costs no MP. If you are constantly spamming esuna for every poison it can be a pointless drain.