I think most people who try heroin or Scientology suffer no lasting ill effects. If it worked on most people Scientology would be a lot more virulent than it is.

Both are true. I'm as unlikely to recommend Scientology to people as I am to recommend them heroin, though. (But, kids - fifty million dead junkies aren't wrong. Opiates are great! I'm a big fan of codeine when my back's playing up, and I have no doubt heroin would be even nicer.)