Dopamine works best - esp. sterile injectable medical dopamine. Careful only to put about 0.5ml for every three inches or so of cactus, and inject from the base to the top (otherwise, the cactus can die). Wait two weeks, then serve. Chances are that doping trichocereus does boost the mescaline content a huge amount, however, since biochemical systems tend to have some homeostatic systems in place, but it does seem to help.