Neale wrote:
If you don't want to pickle them, someone was telling me about
de-husking them, then burying them in a bin full of sawdust mixed
with salt. Has anyone tried that?

Not been lucky enough to try it, but I do know walnuts we buy have
been stored for a long time -- even a year, I understand. I've heard
of the salt method, but don't believe in it, since it would attract
moisture, which you don't want.

I had a look on the 'net under "storing walnuts", and all seem to
agree that you have to spread the nuts out to air-dry for a couple of
weeks before storing them.

Getting the husks off first is important: I hadn't realised that
leaving them on would spoil the flavour. And it seems to be quite an
operation!

Apparently they're dry enough when the dividing membrane inside snaps
crisply rather than feeling rubbery. Then it seems you can just hang
them up in cloth bags or put them in cardboard boxes; a smaller
quantity will keep in a closed container in the fridge for a year,
they say out there.

All the sites agree that the nuts will pick up off-flavours if
they're stored next to other things. This would seem to be a strike
against sawdust, especially from softwood or treated timber.

I think you're very lucky, but it seems you're in for a bit of work.
There are some nice-seeming recipes on the Web, too.

Mike.