Ummm.......I recall reading that when the body of Becket was examined after he was murdered in Canterbury in 1170, it was noted, with approval, that he had a "good crop of lice"
I'm sure we can all think of times in the past, when we haven't been able to wash properly for a couple of days ( mine would that journey on the Orient Express in 1976 ! ) and how "uncomfortable" it felt. But if people really didn't wash properly for months on end, they must surely have developed sores and other more nasty things, especially in our "moist regions"
So, while I can understand that after the Romans left, us Brits didn't have all that lovely hot water, we should still have kept ourselves as clean as we could.