"Unless I am feeling utterly miserable on day 5 (Sunday), I fully intend to go to at least 10 days."
Bad idea going into a cleanse! You are sure to feel "utterly miserable" at some point - that's what detox is all about. Better to decide on a stop date - mentally prepare for that - because if you end because of feeling low you will only prolong the discomfort and stop the detox. Just remind yourself that those miserable feelings will not be solved by food. Water is the best defense against detox, and in a pinch, do an enema for almost immediate relief. Exercise is another great way to stay sane during a cleanse.
Believe it or not, I didn't start feeling really good until day 12. I agree with Pepe, that if you're interested in such an intensive cleanse, why not take it past the "minimum"? I went 21 days on the Master-Cleanse my first time and it was fantastic! Most of those days I wasn't hungry at all, and even when I ended it, I really didn't want to eat yet.
As to using the SWF (Salt-Water-Flush) and the B&P shakes, I certainly wouldn't be adding B&P without the SWF (Salt-Water-Flush) or the lax tea! Talk about impact!! It's best to flush the junk OUT, and B&P's don't flush, as far as I can tell. Since you're not eating anything the fiber content is low, thus the need for flushing agents.
Oh, and don't forget: WATER, WATER, WATER!! ESPECIALLY on the UC.