Can't help much with TX parks but we often dry camp and find if the boys use the outdoor/public facilities and the girls are careful with the indoor facilities 5 days can work w/o a midweek clean out. You mention State Parks and we find these usually have nice restrooms w/ running water and often times shower facilities.
Personally, I agree completely w/John. Never have and will not ever own/use a tote for black water. Actually camped next to a couple who did and had to ask them to move the stinky dang thing to the other side of their camp
