Yoni is a term used in hinduism that means vagina.
Yoni steam bath is a great way to rejuvenate your vaginal tissues. When dried herbs are placed in the hot water, the volatile oils that contain medicinal properties are released. A yoni steam works by applying heat, as well as moisture that caries these volatile oils, to the exterior tissues of the vagina (the tissue referred to as the vulva). The warmth and moisture increases circulation to the labia, causing it to swell and expose the inner labial mucus membranes. These tissues are very porous and absorbent, and the bloodstream picks up the volatile oils can carries them into the inner reproductive system, including the uterus.
Many women have reported that the yoni steam bath greatly improves their menstrual cycle and makes it less painful.