Methods of powdering Japanese Knotweed at home?

Hi, I'm looking to grind my own knotweed root to help make my longterm lyme treatment more affordable. I can't afford a vitamix or other expensive food processor. Does anyone have any experience using a corona style mill for grinding JK or other roots and barks? Like this one: corona mill ebay

Other suggestions of an a affordable way to powder the things we wildcraft would be so very appreciated.

Thanks so much,
Murph

Thanks for the response Pete! Do you have any suggestions on the type of coffee grinder?

Also, I was thinking about starting to gulp down the herbs directly myself rather than using the capsules but I was wondering if capsule might be a better way to go for any reason. For example wanting to get the medicine lower down in the digestive tract first before it starts being broken down/absorbed by the body. But maybe that's a topic for another thread...