Blasting is used a lot for a satin surface finish. I use Trinco ‘Trin-Mix #4’ which is a mixture of glass beads and aluminum oxide as a fine general purpose media – nothing heavy duty like rust from steel, mainly bike stuff including aluminum, and stainless and bronze boat hardware. Sometimes I blast stainless pieces to clean up a little, then do a full polish on my Baldor buffer. No sanding in between. Trinco has dozens of different media available, everything from steel shot, steel grit, to cob grit (crushed corn cobs), crushed shells, and a new dust free plastic media. Trinco has ten different grades of glass bead media. Trinity Tool Company, Fraser, Michigan.
Blasting spokes would really take a while and use a lot of air. Easier would be to knock down the polished finish with something like a fine scotch brite pad. Just do it by hand, or maybe chuck the spoke in a drill press or a lathe if you’re careful. 220 grit wet sandpaper would do well too.
I've used Buchanan stainless spokes which came kind of satin. Full polish is extra. I like the satin because it does look like the original zinc or cad or what ever plating. I do like the chrome nipples however, not stainless.