The grass known in Thai as Ya Hee Yoom, or “Ya Repair” (literally the grass that repairs) barbed grass (Centotheca lappacea) has long been used in Thailand to treat women post labour, as it is believed to help heal wounds and tears on the labia, and help to tighten the respective muscles.
The traditional method of application is to burn the grass, dry or fresh, along with wood fuel until there is smoke coming up. The woman patient, wearing only a sarong stands over the smoke to receive treatment.
Another way to apply the grass for treatment is boiling it to extract its essence in the form of a juice.
It is thought to offer the same benefits as smoke. The juice does not have much of a taste so it can be sipped it all day long like water.