reid.vfx- if you already purchased the program I recommend you go to the interview and watch the first one, with (OMG I forgot his name-) Cameron! That's it. He describes how kriyas felt for him, and you can see it's a manageable issue and not as dramatic as reported.
In fact, I saw a video about a woman that was having 'kriya' problems, was very popular in youtube, and later was debunked- she was exaggerating the 'problem' and it stopped when they stopped filming. So don't let the horror stories freak you out, I believe most of them are exaggerations- people simply like their attention, if you know what I mean.