Originally Posted by pete_2
So he says not to pick anything up, does that mean at all, or just as soon as you enter that one area with the balloons?
"Upon starting the game and taking control of Isaac, feel free to pick up items up until you reach the room with the balloons. From this moment on, do not pick anything up other than what you're duplicating, until you are satisfied with what you have, and are ready to move on. Unfortunately, this means you can't duplicate the Gold Semiconductor that the boss drops."
Just to clarify: you start a new game with the intention of doing this trick. You can pick items up until you reach the room with the balloons, as seen in the video (and I'm not referring to one of the times you revisit this room; I mean the very first time you reach it). You do not pick *anything* up from this point on, other than what is shown in the video. Using kinesis to move stuff about is fine, but do not actually collect anything.
I may make my own video that touches on a few more details not clarified/covered, when I have some time, as I'm considering redoing this exploit and utilising the DLC weapon trick so I'll have a lot more credits. 200 power nodes gets you a million credits, which is more than enough to constantly buy large med packs/ammo/stasis packs whenever necessary.