Master Cleanse. Is it ok to use the lemon juice concentrate they sell it in a plastic lemon instead of fresh?

i did the cleanse...i use real lemons..you might want to check whats in the concentrate..they might and sugar or something else...best way to do it..either make a big jug in the morning that lasts you all day or a medium one in the morning and another around your lunch time...you can also drink water