urgent san pedro cactus extraction (citric acid) question

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Swim has 500 grams of peruvian torch powder and plans to do an extraction on it using erowids extraction for dummies. it say you can use citric acid wich is what swim wants to use. well swims been looking everywhere and only came up with this stuff called fruit fresh wich has citric acid in it. among other things. heres the ingrediantsextrose ,Asorbic acid (vitamin C), Citric Acid, Silicon dioxide. will this work for swims acid in the extraction?
heres there website http://fruit-fresh.com/

Thank You