Hi
For a quick result and if the wheel is built up, use the acid solution (like you use on alloys etc), then use a worn household sponge / scourer and finally blast with a jetwash / hose.
You can then put some polish on a rag, put the rag through the spokes and pull / push the rag and give them a quick polish that way.
This is pretty much how you clean motorcycles.
NB - meths is good added to water to clean items aswell.
Hope this helps.
J
