i found a few ways to prepare it, but could not find consistent answer to the amount, or the best and easist method of preparation

Experiment! :)

If you're willing to put forth some effort (which will save you from having to digest what I've heard described as 'death flavored snot'), look up foaf's extraction tek. It's super straightforward and doesn't take much chemical no-how. There's also an easy extraction guide on Rhodium, but without pictures. I'm not sure of the yields on that method, either, but it might be worth a look.