Downward-Draining Herbs (Intro)

Based on your knowledge of its category, what are the properties of Gan Sui (kansui radix)?

Gan Sui is a Harsh Expellant. Herbs in this category tend to be toxic. Pick the answer with toxic in it.

Source: Bensky, D. (2004). Chinese Herbal Medicine: Materia Medica. Seattle, WA: Eastland Press. pp. 251 [Q554]