On grips, I can tell my own "story". For at least a decade of playing I tried to use the textbook grip. Meaning either the loop grip of index finger and thumb or the cradle grip of all fingers. And for years and years I had trouble with my wrist, I kept on having unwanted wrist action which enventually ruined my stroke in intense tournament matches. Then by experimenting I found my own way of gripping the cue, very unorthodox with my index fingertip supporting the cue and finger pushing the cue towards the thumb finger joint near the fleshy skin area (don't know how to describe it). After some practising I noticed that for some reason I got rid of all my unwanted wrist action with this change and never had any since (well occasionally but very rarely).
My point is that you can experiment with your grip hand, but realize that you cannot judge your new grip only after a couple of succesfull sessions. I thought many times that I had found a grip which would always work, but next time it didn't work at all. Eventually I somehow came up with that grip and used it ever since.
Just my two cents on subject.
EDIT: Thought about it, it's difficult to keep the wrist unmoving through the entire stroke. If your grip is too tight, you get not enough stroke action. If your grip is too loose, you might have some unwanted wrist action as well. IMHO it's not the looseness of your grip (though it helps), it's the looseness of your shooting arm. If you have a stiff arm, but loose wrist/grip, you're going to have quite an unaccurate stroke.