The tea might make you nauseous, I would try it out first in case you puke at the concert.
The highly purified stuff IMHO is not even the same stuff as dirty sanchez = (dark brown, has GAK impurities). Mescaline is supposed to be white to translucent, not brown. The highly pure stuff at only 200mg had my girlfriend and I laughing uncontrollably for several hours, we've never gotten that strong an effect from brown sanchez. Talk about a really fun trip. It was identical in strength to *good* low dose acid at 1 hit. One of the best low dose trips we've had. Me! had theorized that it's the compactness of the ultra pure cystal matrix that accounts for its potency, he was told this by the "mescaline" during a trip he had once. Recrystallize your brown sanchez in a beaker of boiling MEK in a fumehood, then to room temp, then to fridge, then to freezer, recover ultra-pure crystals. If you don't know chemistry lab procedures, making pure clean Mescaline will certainly teach you how! The light tan stuff resulting from a simple acetone cleaning on the brown sanchez is very good too. There is way less nausea and stomach ickyness at higher doses with the light tan to pure white/translucent crystal than the brown IMHO , in fact there is none for me with pure stuff when taken in divided doses over a 1.5 hour period. Others do just fine with brown sanchez, depends on your individual sensitivity. Only one way to find out, try it yourself. If you don't like it, just clean it up by re-crystallizing it, problem solved.