That is an old wife's tale. First of all when you bathe as often as I do? You never HAVE dirty water to begin with. It is not uncommon for me to bathe as much as 3 times a day. I do massage. I know skin and I have no zits nor clogged pores. I am good. Plus I do skin brushing, and loofah and if I feel scummy, I fill the tub and rinse. I never do though. Soap is not dirty. And it is possible to rinse with a wash rag. Good stimulation for the blood. The blood cleanses the skin from the inside to the surface. So the heat of the hot water in the tub actually cleanses the pores. Just follow with a cold rinse and you are good to go.
Normally I take 10 minute showers....now that it is colder out and the bathroom is colder...I will soak in a long hot shower for around 20 minutes or so.
One to three minutes depending on the amount of water in the tank. Once a week, longer in order to wash my hair. If I could have one luxury, it would be a bath All our internal house water comes from what we collect on our roof of 11 by 9 meters. Annual rainfall usually above one meter. I remember the worst drought on record in 2002: no showers then, just used a bowl and washer. Had to take clothing to the laundromat - astronomical price everytime.
How do you wallow around in your own dirty water? 
WM BARR . =ABSOLUTE TRASH 