I have a whole lot of knives.
Most simply live on a shlef when not being used. I sometimes rub the blade down with a product like tuff cloth. I rarely lube my knives. If they get wet I make sure they are totally dry before storing and maybe add a little lub to the pivot.
I find if a folder is clean and dry it does not require much in the way of lube. Most blades of mine are stainless.
I have never heard before that folders should be stored any other way but closed.
Some folks keep their fixed blades out of the sheath to avoid pitting.