There's more knowledgeable people than me out there but my knives are in decent condition. My CAK is going on 10+ years. My opinion is it usually doesn't need that much special care.
Rule #1 and I hate that it even has to be mentioned: absolutely never any dishwasher. Big no no. Glad that didn't happen to one my khuks but I've nearly had an aneurysm when I found a (formerly) nice wooden chef knife in there. Anyways. Just don't.
Likewise, avoid needlessly soaking in water. Sometimes it rains and you need a tool, that's totally fine, just wipe it down when you're done if you can. Soaking it in the sink for an hour, not so much.
Oil now and then. Everyone's got their thing, but I'm happy as long as it's foodsafe and doesn't go rancid. Stuff like olive oil goes rancid pretty quick.
Sure my CAK is mostly used for splitting wood, but I've had to prepare a bird with it now and then and it was nice not having to worry about whatever product might be on there.
I'm sure motor oil would be a great protection, but I don't wanna eat that.
I prefer non-petroleum products, never been a big fan of BLO personally and most mineral oils around here are scented baby oil which I don't fancy much.
Me? I usually have a good supply of coconut oil so that's what I use (works great for dry skin, massage, etc.)
It's pretty thick though.
I'd probably avoid lubing the pivot of a folding knife with it, but a khukuri doesn't have this problem.
I don't soak it, just a light coat and a buff every few months or after a particularly rainy day (do dry thoroughly before oiling). I also use it on the blade, I'm just lazy. I apply liberally on the blade, some will get in the sheath too.
The handles? I always buff them dry after oiling. I want the oil *in* the wood, more than *on* it.
Always curious as to what others are doing, so chime in.