I can't add anything too helpful to the excellent comments from @Simon082 @RDalman @birdsfan and @tostadas above, especially as I've never tried spalted wood. But I will say that I've stopped using Tru-Oil as it just feels too unnatural too me, and I have had a good result - in terms of keeping...
Hey mate. I have a 240 nashiji SKD yoshi I've been meaning to sell but have been too lazy to / haven't quite been able to bring myself to. Based in Aus. Purchased here: https://www.kitchenknifeforums.com/threads/yoshikane-skd-gyuto-240mm-nib-australia.60653/
Shoot me a dm if still looking.