h4mmy86 is right. Like pasta rollers, you should NEVER use water or any type of wet rag to clean these types of equipment. No need for oiling the rollers. After each use, wipe them down with a dry cloth and store in a dry, cool place.
I made the mistake of trying to clean mine when I first got it (it was used) and it started rusting like 10 seconds after I got it wet. I ran some dry white rice through it a couple of times and that knocked the rust out.
Now I just clean with a stiff nylon brush every time I use it and otherwise ignore it. Also, I never condition my malt.
fwiw, you can run conditioned malt through a steel mill, just reserve a half pound of un-conditioned base malt to end the crushing session. You'll get nearly all of the benefit of conditioning without leaving the mill damp...
My three-roller mill achieves a pretty efficient crush without much shredding of husk, so I'm unconvinced that conditioning would improve much of anything to be worth the effort. Others might disagree.