i have been using caffenol c as a print developer as well as the 130 --.
it's a little quirky but fun and environmentally friendly as well -
I would be careful in saying that a coffee based developer is environmentally friendly. You must also consider the effect of coffee growing on the environment. IIRC, rain forest is destroyed to make way for coffee plantations. In balance I think more harm is done than good. Things are never as simple as we first imagine them.
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.