I did, and I would not recommend this book for a beginner. The only reason is that during these invocations one, especially a newbie, has no idea if who they are calling is what they are getting.
I wish I can speak from a 1st person point of view, because this has never happened to me. But for someone to daily, repeatively, almost nod off in meditation and begin doing an invocation, according to most of the "experts" is asking for trouble.
I haven't finished reading the book yet but probaley will by the end of tonight. I'm working a 2nd shift tonight with not much to do.