Uh, gee....I don't own a Japanese sword and wouldn't tolerate being slapped on the head for much, especially not an innocent mistake. I don't need that $h!+ to learn what is right and what is unacceptable. I digress... (and I just found out this forum has an automatic bad word sensor that substitutes **** the lowly asterisk. How bout that!)
However, the question was "how to clean and protect".
Finger oil comes off easily with any kind of solvent. You won't hurt any kind of steel with the solvents in, say, something cheap like $2.50 brake cleaner from Pep Boys. This will ASSUREDLY take off any oils. To the point the metal looks dry and dull and whitish. Apply rust preventive or oil or something immediately after wiping down after solvent evaporates. However, don't use anything with ammonia.
If there is very light rust, Flitz (not "Fritz", unless you are Japanese) or Happich Simichrome polish will take it off and leave a nifty, well, uh, polished finish.
The ABS guys and a lot of others use Renaissance Wax to coat their fine blades/handles. It is supposedly museum quality wax, and is pure white in the metal cannister, and very clear when applied. I've heard other makers say they use Johnson floor wax. Either extreme. Renaissance actually smells good, and is pretty good stuff, and it is damned expensive (around $20 retail for a 200ml can about 2" diameter and 3" tall.
(people spit when they talk ... the ABS guys talk about "spittle"...that being tiny drops of spit that rust their blades during knife shows. Hilarious. And true. I love carbon steels.)
You can try Tuf Cloth or Marine Tuf Cloth, if you don't mind the mild smell after it dries and then buffed a bit. Or even Break Free lube, again, a bit of smell, but buff it after it sorta dries.
[This message has been edited by rdangerer (edited 08-01-2000).]
[This message has been edited by rdangerer (edited 08-01-2000).]