I would wipe the blade down with some type of gun oil. I like Remington "Gun Oil" it comes in a green and yellow spray can. They have what they call a "Dry-Lube" also that is very nice. It is a synthetic spray lubricant that is made for triggers and things for guns that you don't want a bunch of oil jamming up and coating heavily. I spray all of my swords and any blade down with dry lube after I give it a going over with light oil. If you desire to clean it just handle it like you would with a gun restoration. If it has any dirt in the heads of the bolts or anything you can use HOT soapy water and a toothbrush to brush out the dirt. The hotter the water the better because it will evaporate quickly. Now as fast as you can dry it off. I use a spray nozzle hooked to an air compressor then I spray it down with oil. If you dont have an air compressor I guess you could use the canned air duster for keyboards to dry it off. If you do that and keep a light coat of oil on it it should be preserved.