I've had folks try my changa with no problems, then later they tried it again and got that awful lung tearing/ripping/burning feeling. One guy had  even left  his body and was still feeling it in the other realm...  he said he would not try smoking it ever again after that. I've had this happen as well, and  it seems to be partially related to how dry it is. Now I am very careful to always take test hits before  a full hit. And in general I abstain from smoking changa entirely, to protect my lungs. If I'm serious about the journey I  will do aya.