By and large little to nothing needs to be done to modern straight razors scales. Of course with everything there can be exceptions, but for me personally I do not apply anything to my new straight razor scales. The only time I apply a product to straight razor scales, it is a VERY old horn scales razor, and the horn looks very chalky/dried out. In this case, I apply just a tiny amount of horn oil (see picture below) to the scales to give them a brilliant shine/luster, but by and large this is not necessary. Some recommend treating ivory, and some woods with oil and such, but I haven't found this necessary.