I enjoyed Jan's take on this effect.
I learned the basic principle 20 years ago from a
friend who'd independently reinvented it, and I remember how hard I struggled with learning it.
Jan's teaching is better than I had then, although I think a slightly different approach might help
some learners (the more analytical ones).
I've taught an effect with this principal for 15+
years, and I realized quickly: the instructions you give are absolutely critical ... more so than
for any other effect I do. For me, since I recognized the technique, my purchase was motivated by
a hope that I'd learn from a professional how to handle problems. (Indeed, watching one of the
demos, you can see a point where a major problem *almost* occurred.). But, it lacks that. Sure, I
have outs for a lot of effects. But I haven't put the time into thinking about a good one for this
effect (and, the out would vary from when you use the technique for playing cards vs. words), so I
was disappointed not to find one here.
There is just one (and only one!) point where you have to make sure that happens what you want that happens... this is why I address explicitly the pantomime, using your two forefingers while standing with your back to the spectator. I really found that this makes the procedure very safe!