Here is my Tek for Wachuma,
I cut off all the spines. Rinse the cactus well, you can even use tequila or vodka to disinfect it.
Next, I use a knife to core the cactus. I cut down each side to remove the inner core - the core can later be boiled to make a cleansing bath/shampoo to prep for ceremony if you wish to have that kind of intention.
Next, I peel off the waxy outer layer while leaving behind all the vibrant green flesh (the green contains the highest mescaline content).
The simplest method is to just put all the parts - minus the core - in a blender or food processor with a cup or two of water. Otherwise, its a bit of a process to cut off the green layer then cut those parts into small chips and boil both the green parts and the slimy white parts (just not the inner core)
Then, I put all this in a big ass stainless steel pot and fill about halfway with water.
I bring this to a minimal boil - hover closely as it will foam up. After it foams, it will calm down. At this point, I squeeze a bag of lemons or limes into the solution. The lemon juice brings down the pH of the water, making it a stronger solvent, but also prevents gastric upset that Wachuma is known for. I Also add a few tablespoons of fresh-ground black pepper as it potentiates the molecules.
I simmer this just enough so you see the solution move a lil bit, but nowhere near enough for a boil. I do this for about 3 hrs. Then I let it cool and place in the freezer. The process of freezing helps splinter the vegetable material so the solvent (lemon water) can better infiltrate the vegetable and better extract the mescaline. Then once its frozen, I reapply the pot to the stove and simmer again for about 6-10 hours.
Strain, serve, and freeze the rest
Now the real trick is to never boil the cactus. I've seen several people make weak wachuma by boiling their tea. I find much better results by simmering - I like to see the solution move from the heat but not boil any bubbles.
As for serving, according to the Native American Church, the 1st cup cleanses you of all energies you bring to the ceremony
The second cup is you symbolic death
Then you use hapay (tobacco snuff). You will probably purge at this point if need be.
Then the 3rd cup is your rebirth.
Bless your life