I believe that it helps your mind from wondering, but only helps. You can chant, photo-foucs, flip and still wonder... at least I can.
I make sure that I have I AM RELAXED in my chant, but not just relax. I sometimes do 1-2-3 or 3-2-1. I always have I AM ALERT, and I NOTICE ALL THE MATERIAL. I usually have I'M MAKING THIS MATERIAL MINE.
I sometimes re-inforces the tangerine, I do this when I want to increase my feeling that I'm taking the material in.
I sometimes chant a line of purpose, I do this if I notice myself drifting.
If I stumble during page turning, I say things like, "This is okay, I'm taking it all in.", "I'm relaxed and my see it all.", "All this material is becoming mine".
I'll re-iterate that I always have RELAX in my chant. I notice muscles loosen almost every time I say it. I put more than just relax in my chants, because repetitive relax statements will start me on the road to sleep.
So alesT, my answer is yes I basically agree with you. 
