Been there
Yeah..I've done this. Couple things.
First- Don't do this at a concert, total waste. Do it at home with your girl (in the woods if you want, but have lots and lots of water and supplies.
Second- Don't listen to these people who have no idea wtf they are talking about when they say they don't think it would be a combo. It is THE combo. It will be the cleanest most healing roll of your entire life.
It is incredible... When we did it, we dosed the cactus, peaked four hours in, tripped very nicely for another three hours after that, then dropped our pills while still goin strong on the mesc. There was virtually no come up, just started talking more and more, and before we knew it we were unearthing damn near every little mental problem we had, and fixing them with ease. Unbelievable empathy like nothing you've ever felt. Absolute comfort, didn't even want to smoke bud, it just clouded things.
Sacred is the cactus
Blessed are we
It's not 'just another drug'. Show respect for the gift from God, don't take the stuff recreationaly, it's a sacrament.