"Paint thinner," is what McCoy has to say about that, as he reaches out and finds drugs in order to achieve what Charles is explaining to Steve, trying not to think about what would happen if this were him and Jim, if Jim or any of his closest friends were ever like this. "Once it gets delivered..." Which is where McCoy needs Stark to help, "the light charge is just to try and reboot the brain, restore factory settings. If he's out cold, he shouldn't even feel it."