What you need:
A bath-tub and some bath salts or hot spring powder. I get mine from hot springs i visit in Japan. The one on the right is from Noboribetsu (Hokkaido) and the one on the left is from Ibusuki (Kagoshima, Kyushu). Hot springs in different regions have different components.
Pour one satchet into the water and it transforms into a hot spring at home!
Fill the tub halfway with hot water. must be hot like hot spring but not scalding until you get cooked. sit in the water with legs straight and palms in water. the water level should just cover your belly button so your lower body is submerged but upper body is above the water.
Wait 15-20 mins. You will be drenched in sweat!
Drain water and wash body with soap.
[P.S.: The correct way of using a hot spring is actually to shower first then soak. But this is a detox ritual you do at home in your own bath tub n you will sweat a lot so it's ok to shower after.]
My ex-Japanese language teacher taught us this and I try it when i remember. it's supposed to be good for health and complexion =) try it!