Do HI blades come treated or finished? The villager I got years back I could feel was just raw wood but the other two I have feel polished or maybe a hard wax finish? I'm curious so I know how to maintain the wooden handles.
As far as I know, when polishing the blade they run the same method over the wood as a light burnish, but there’s no real treatment like a varnish or oil or anything. I know much of the wood they use is fairly oily, when sanding, the dust tends to clump rather than blow away which indicates moisture.
You can read about various people’s treatments to the wood handles. I find the wood varieties used are both very forgiving and often very gorgeous. Personally I just rub a bit of mineral oil over the wood once a year with bare hands to keep it moist and call it good, but there’s been a couple gorgeous models I’ve received lately that I think deserve better treatment.
Either way, mineral oil is a fine thing to use on a working handle. I haven’t heard of it softening wood before but I don’t doubt it personally. Mineral oil doesn’t polymerize or dry, it just kind of lingers around and keeps the wood hydrated. Perfectly fine if you only occasionally treat the handle or don’t care about looks a lot.
For a more permanent or lustrous finish, you could sand off the outer layer of the handle (220 or 320 grit is plenty) then refine to 400 grit, apply Tung oil or Boiled Linseed Oil, wait for it to cure between 1-3 days, burnish that in with 600 grit, then apply more oil and repeat until it looks good. I’ve seen some amazing results come from this.
If you are interested in one of these oil finishes then you must get rid of the polished layer, or if you’ve applied it, mineral oil. As mentioned, mineral oil doesn’t really dry or polymerize, though it does evaporate or wear away given enough time and friction. Similarly the polishing method they use seals the grain somewhat and keeps oil from seeping in. Unless you soaked the handle for days, I’ve had perfectly fine results just sanding down the handle with 220 grit sandpaper and mineral spirits/acetone. If you have soaked the handle, just burnish it and leave it be. Mineral oil can be trivially easy to remove in light amounts but a bear to remove in excess, expending much mineral spirits and elbow grease, as you just have to do the same method prior with much more gusto. But even that soaking method is perfectly fine for something like a knife handle. Something like a table or shelf or heaven forbid a floor soaked with mineral oil is a totally different story.
Not speaking as any sort of wood authority, just from experience.