Comfrey Running Rampant, Can I Sell It?

Years ago a neighbor gave me some comfrey for my garden and over the years it has multiplied on its own! I keep slashing it down as a weed, but began to wonder if there is some better use for it, and if I might harvest it and sell it to anyone. It would really be smaller scale but thought would ask if this is something to persue. There is really quite a lot of it, and it seems to love our soil and growing conditions. I see that drying it tricky, but I do have indoor facilities to hang and air dry herbs.

The main question I have is "what is quite a lot?" A 1/4-acre set is not really very much comfrey, and probably not worth any effort toward harvest and sales. Goats will eat this easily, while cattle will not. The roughage underleaf is not palatable to a cow. It is, however, one of the best foods a cow could eat for total amino acids in the diet.
To dry it from a field, one normally puts a light wilt on the comfrey before picking it up with a flail chop and then taking it to a dehycrator, hop kiln, or tobacco dryer. All will work. If you try to dry it in the field it will rot. If you do not put a light wilt on it, it will probably rot in a dehydrator.
It is not an easy handling herb, as the indol alkaloids will cause it to blacken and then rot before it can properly dry. This is due to the high muscilage in the leaf. The root part of this plant is considered poisonous with oxalic acid pyrilozine alkaloids. The root can be used externally, with facial creams and other topical applications.
What I am guessing is that you have only small field, and I would use that for goats. It is not easy to eradicate, and spreading it is quite easily done with a plow. I would not bother with anything less than two acres.