During the Challenge of Atlas after you cross the bridge and pass the saw room, there will be an enemy at the bottom of the tower. Don't kill him, just go to the ladder near the wall. Position yourself so that you are between the enemy and the ladder. Use the square, square, triangle combo to take him out. Make sure you kill the enemy above the ladder. Once you kill it, it should hit the ground, then bounce back up getting caught in this bounce. If done correctly, it will continually release red orbs. Once you get the glitch going, just stand there for about 10 minutes. You will get the max amount of orbs, 199 full red bars which is 59,700 orbs.
Skip conveyer belt area
When you first walk in to the conveyer belt area right before pandoras box you barely go past the entrance as to not activate the battle with harpies and arrowers. Immediately walk as far as your can to the left or right with running into a conveyer belt. Then walk forward next to the conveyer belt until you reach the first pedestal. Jump on it and you should be home free. Now you can liesurely walk to pandoras box without a battle.
The whole idea is that there is an area near the entrance that if you walk in it you will initiate the battle. By walking as close as you can to the edge you are not "tripping the trigger" per say.