DMT makes a diamond impregnated metallic "stone", in a variety of sizes, shapes, and grades. I have several, ranging from full sized bench type, down to folding double-sided/differing grades of coarseness for my field kit, and an absolutely invaluable round rod type I use for dressing my serrated blades, or just touching up a cutting edge, much like a steel. Available just about everywhere, they can be used dry, although I prefer to use water when actually repairing an edge. They never wear out. That having been said, I'm also fond of both the Washitas and synthetic stones, which require oil to prevent clogging; it all depends on the job at hand. Lots of options are at hand, and although I prefer to freehand my steels, the Lansky line is also quite good, too, from what I hear...
Good Luck.
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