Well a few notes:
1) Do be careful when buying extracts/incense of any mescaline containing cactus. Why? Because in that form there is a semi-legal argument that you are going to use it recreationally and therefore can be arrested. Just buy the actual cactus, A MUST!
2) Arguments for the peruvian torch to san pedro are all over the web. Try both for a better understanding. Make sure you identify them properly (ebay, some crappy sites) will not sell you pachanoi (san pedro) and pervianus (pervuvian), but will advertise as such. Identification is really important.
3) After you purchase your weapon of choice, what you want to do is not water it for about 2 weeks, or if bought unrooted, toss it into a burlap sack for the same amount of time in a dry, cool place.
4) You'll find a million extraction processes, but here's a few tips I've personally found very useful:
a) Do not use the core (duh)
b) Prior to the extraction process skin and chop up the cactus and put it in the freezer, then thaw, freeze and thaw again, prior to doing whichever extraction you choose.
c) Do not overheat the cactus, heat kills mescaline.
d) Don't forget lemon juice/citric acid.
Trust me, just buy the cactus itself (no powders), leave it alone for a while, so it can become more potent, and then just extract. I feel like in the process you get a better trip because you work for it, so you get the cultural aspect of it, and you earn the trip. Good luck, and you'll enjoy it.
