In Lawrence of Arabia when asked about the secret to snuffing out matches with his fingers without it hurting, Larry responds The trick, William Potter, is not minding that it hurts.
The trick (we all learn this in our middle adulthood) is not minding what others might think when we scratch our private itches. Everybody itches the way everybody poops. It's not about hygiene, I itch like fire coming out of the shower (my doc doesn't know why). If it bothers someone that you're a human ape thing like the rest of us, they are not worth your time.
An interesting hypothesis. The alternative would be to shower in tepid water and come out feeling a bit chilled. At least now during the winter. Usually it's the summer when I itch coming out of the shower.