Well out ferreting the other day came across a Black Walnut tree with loads of nuts fallen and still on the tree. Well they have a green husk that quickly goes black as it's full of tanning and other shit, well read up on it and you have to remove the husk. Did this and just blasted them with a power washer but Lol you see my hands, they are stained to f**k looks like I have frost bite. They are very different looking than an English walnut, hope they taste nice after all this trouble.
If any body knows a good way to remove the stain please tell. On line it said Lemon juice and salt, well