Downward-Draining Herbs (Intro)

What special cooking instruction should be followed when using Huo Ma Ren (cannabis semen) in decoction?

Huo Ma Ren is a seed with a hard outer shell. It should be crushed first in order to release the oils that lubricate the intestine.

Source: Bensky, D. (2004). Chinese Herbal Medicine: Materia Medica. Seattle, WA: Eastland Press. pp. 245 [Q550]