Well my research is by no means exhaustive ... but ... I chucked some old spokes into a bucket of Stabilised Chlorine Granules ( swimming pool type stuff ) and water that I had mixed up ... stirred it and left it for 10 minutes and they came out a treat.
I'm not totally convinced that the spokes weren't 'just a bit dirty' in the first place ... so I need to find some proper 'tarnished' ones and have another go ... but there may be some possibilities there for all those who hate cleaning spokes :-)
