If you have a beer/wine homebrew shop in your area, you might check out their bottle brushes. You can get brushes from 3/16" to 2" dia. that have long handles so you can bend them to reach almost any area around the wheel/spokes.
I use one of those Mother's mini powerballs and chrome polish. Makes it a quick job, gets into every little nook and cranny, even keeps the spoke nipples all clean and shiny-like
