the best way to do this achy this way is to find a nom bottle as close to a checkpoint as poss,i found one bottle as soon as you spawn on Act 4 Chpt.2,as soon as you spawn,theres a reload point on your left,and 2 waterfalls coming through the ceiling,choose the one on ya left,walk straight through it and your bottle will be on the floor, right in front of you.Now just hit 'x' to drink,or shoot it and hit start,make sure you press restart checkpoint,and not chapter,,,have fun.It will take roughly 6 mins using my solution and part of the game to get both achys