So now I have a dilemma, how do I get the outer skin off down to the shell
for drying, especially without turning the whole neighbourhood black from
the juice??


These were some of last years, check photo at
http://www.gb-online.co.uk/plant_cen...tos/walnut.jpg

Store them in a greenhouse (protected from squirrels) for them to dry
thoroughly. You need to wait until the skins are really dry and black,
and they will just fall off.