Can you elaborate? I don't follow.
In every tek I've ever seen, not to mention my own experience with natural products in the lab, you get more than dissolved alkaloids in solution when you make cactus (or any plant) into a tea. When you leave a cup of tea or coffee out too long and the residue evaps, you don't get caffeine crystals (I wish,) you get a bathtub ring of flavonoids, etc. on the bottom of the cup. With cactus, you have a TON of mucillage that no amount of low tech filtering can remove, and it inevitably becomes a dark, gooey mess in my experience.