I need it for my venus fly traps!!!!
It is often easier to combine items than it is to separate items. The best approach is to buy the correct product the first time. Don't waste your time trying to remove fertilizer from perlite. I have never seen horticultural perlite sold with any additives. Usually, it is something else with perlite added. If you have managed to obtain a perlite with fertilizer product, it can be used for other things --- just not carnivorous plants. You can create a good mix by combining equal parts of peat moss, very fine pine bark (sometimes sold as soil conditioner --- read the label), and horticultural perlite. Most orchids and carnivorous plants like to be moist but not wet. Excellent drainage is essential.
East way: just buy perlite alone, or at least, not a Scott's Miracle-Gro product, or any soil mix that does NOT have added fertilizer. Harder way. Soak and rinse the perlite several times, allowing to dry out between rinsing.
