that's not enough info...saying "alloy" is like saying "mixture"...of what? 90% of modern spokes are stainless steel, and they rarely oxidize even in SF Bay Area salt air, but when they do you just follow the advice given above. The rest of the spokes are common carbon steel with usually zinc or occasionally a nickel plating, when they oxidize you get both chalky white zinc oxide and good old rust...I like to use a mild phosphoric acid with scratchy pads/steel wool, and only on spokes that are really worth it cause it's a lot of elbow grease. If your alloy spokes are something else, please let us in on it.