This is such a funny concept to me, I mean for Daniel Day Lewis, or Sir Ben Kingsley I can see no one saying anything, but imagine third girl from the right in 42nd street constantly acting that way, or "refidgerator repair guy" in a comercial. I would be afraid of overstepping the directors vision, and making an a$$ of myself as well.
I always limit my method to the time immediately surronding the performance. If it works better for you to do it longer, then more power to you, I actually wish I could try.
I stand corrected, you are as vapid as they say.