As you can imagine, I make my own walnut stain from english walnut husks for finishing stocks that need a bit of darkening to the wood.
I am currently 'brewing' so to speak and will be happy to sell walnut stain (not oil!) at £10 + PP per 50ml.
why is this better than shop bought walnut stain? well, it's home brewed to my recipe and,,,well, not shop bought
Please note this is not alkanet, and will give a different tone, but IMHO, stunning outcomes can be had from less than 'english walnut' stocks.
PM if interested please