I've had the best luck with Bridgessii and Peruvians, not to say I haven't come across a particularly potent Pachanoi on occasion.
Think I got my TEK down pat for 14" of live cactus (if the last result is anything to go by
)
1. De-spine
2. Remove the thinnest amount of outer waxy layer (I use a carrot peeler)
3. De-core if desired, cut into chunks otherwise
4. Put remaining cactus material in the blender until it is frothy and without chunks
After step 4, Use only Pyrex containers
5. Add 5x volume distilled water and the juice from 1/2 a lemon to cactus froth and combine in slow cooker.
6. Allow to simmer over low heat for about 6 hours until about 1/2 the water evaporates off
7. This is the tricky part. Having the goo mixed with water for a long period of time makes separating out the sludge a bit difficult. I use 3 layers of cheesecloth with 2 layers of fine bait netting underneath.
8. Collect the liquid and discard the mush; though be certain to get out all the liquid you possibly can before disposing of it.
9. Place liquid in Pyrex bowl and simmer lightly to reduce overall quantity of liquid to your needs.
Be forewarned that there will be a very peculiar smell during the process and the resulting liquid may be the Most foul thing to ever come in contact with a human tongue. Soaking dishes immediately greatly aids cleaning up as well