This was my first time to actually use comfrey for anything. You could call this a "pile to file" recipe too. The first time I planted it (live plant vs. seed), it died. This year I planted organic/non-gmo seeds and was successful. This year however, I am making comfrey poultices to put in my freezer.
First, I grind the leaves in my food processor (worked better than my blender) with a touch of water. Most recipes I found said to add flour to make the "paste." I also read that chia seeds works well too.