According to Health.com, paraquat sold on the train is a three-no product, and there will be allergic reaction after use.

White grass has the effects of stopping bleeding, resolving food stagnation, detoxicating and dispersing fire. Indications: hematemesis, epistaxis, hematochezia, metrorrhagia, leukorrhagia, dyspepsia, dysentery, jaundice, sore throat, sore mouth and tongue, scabies, baldness and traumatic bleeding.