jno, I'm no expert on britains ancient plumbing systems, what I have described above is what I had to use for the first fifteen years of my life until we had a bathroom installed.
I was sent to the public baths (by my mum) twice a week where you could fill this huge bath with hot water and have a really great soak, and clean towels for threepence, I couldn't get out of it because on returning home she would inspect me very carefully to make sure I'd been, the good news was that for being a clean boy I used to get a mars bar.