There is a tradition in Japan of adding herbs to the bath or hot spring, said to help with skin problems, raynauds, sore and tight muscles, arthritis, headaches, nerve pain, etc.
Mixes for sale usually contain these six herbs:
Angelica acutiloba
root
Cnidium Rhizome
Citrus peel
Artemisia Leaf
Gardenia jasminoides fruit
Sinomenium Stem and Rhizome
Other popular herb baths, easy to do at home as most of these herbs grow as weeds anywhere in Japan, include:
yuzu or any citrus,
yomogi (Artemisia princeps),
dokudami (Houttuynia cordata),
shoubu (Acorus calamus)
Image from this
article about shoubu and yomogi bath history (in Japanese).
Make sure you wrap an Acorus around your head to keep the bad stuff away and make you smarter!
Do you add any herbs to your bath?