Bentonite/Charcoal Poultice..Do I do equal parts? Anyone?

Anyone have any answers for me? I know that Uny told me to get the Bentonite for a poultice when I was asking about putting a charcoal poultice on my ankles to try to draw out mercury. Now, I can't find her instructions. Does anyone know if you just mix equal parts OR more of the bentonite. I have some cornstarch to mix with them. I also could mix slippery elm. I think Uny was telling me when we were on the phone. That's why I can't find it. My Bentonite has arrived and I'm ready to go. I'll probably just do my best guess if nobody has the answer. I think someone said NOT to have a charcoal poultice on more than six hours. Thanks for any help.

NB