Daily cleaning up post-collapse
A pitcher and a wash basin are regular items in most country homes even today.Usually they're dusty and not used, but simply decorative. If you've visited a rural area, you probably have seen them:
[link to lh6.ggpht.com
This is the primary way that you'll be cleaning up post-collapse.
Most people will slowly run out of soap. They won't know how to make it, and so because of gathering firewood, foraging, hunting, and working outside, they'll get grimier and grimier.
The best way to get clean is to use a little pinch of wood ash in the water. This will create a mild lye solution, but you must teach people how to wash. Getting that in your eye will burn just as much as soap if not more so.
Some soaking pine needles in water can also be used to clean as long as the solution doesn't soak long. Rinse well in either case.
Because most people haven't planned, they'll rarely have water to clean themselves. Many diseases will occur as well as bacterial skin infections and then later serious infections from coliform bacteria like Shigella or Salmonella.
You want a special basin to use only for this purpose, otherwise you'll contaminate any water used in it for other purposes. A smart prepper will have a special area used, or simply the bathtub with the basin sitting on the closed toilet. Probably by then, the sewers won't work anyway, and you'll need the space.
Because the sewers don't work, you must catch the water and not let it drain out the tub. Probably if you have a lick of sense, you'll divert the water from your tub into a grey water holding tank, and then water your garden with it. The mild soap solution won't hurt your plants, but of course it's more basic than normal, so watch your pH levels.
All greywater used to clean dishes or the kitchen area will be utilized in the garden as well.