Comfrey juice ??

in 1989 (about) I read an article about making a comfrey healing juice. it was simple to make, harvest comfrey, roll the leaves as tight as you could and pack tightly in a dark jar seal to keep out air. place the jar in a dark spot for 1 year. The resulting black liquid was then painted on the affected area, sprain, bruise... etc. I had made one batch and it lasted for over 5 years, I had good results, but I have not made it again. I am looking for more information on it. Does any one know the process I have described?

Cynthia Callahan wrote:in 1989 (about) I read an article about making a comfrey healing juice. it was simple to make, harvest comfrey, roll the leaves as tight as you could and pack tightly in a dark jar seal to keep out air. place the jar in a dark spot for 1 year. The resulting black liquid was then painted on the affected area, sprain, bruise... etc. I had made one batch and it lasted for over 5 years, I had good results, but I have not made it again. I am looking for more information on it. Does any one know the process I have described?

If you are still interested, there is a newer thread here about it, but it calls it Comfrey oil instead of juice. My is just 3 months old, but I am considering using it as I sprained my ankle.