@Scotj009: It was surprisingly easy. I soaked them in a solution of caustic soda for a few minutes until all the anodising could be brushed off, then I went from 400 to 1200 grit wet and dry for any marked areas, then all over with a scotch brite pad, then T cut then Silvo wadding. Whole thing took just over 2 hours
@Scotj009: Just make sure you don't leave them in the Caustic soda solution unattended, I've read stories of people coming back to find their parts dissolved!
@Scotj009: Yes I was a bit wary after reading some forum threads, but I watched a couple of tutorials on youtube and decided to take the chance. Mine literally took 3-4 minutes, I just kept pulling them out and checking them, as soon as the anodizing was removed I put them in a bucket of clean water to neutralise them. If you see me posting any photos of snapped cranks up anytime soon then I'd guess I left them in for too long. :-)
I've found some slightly weeker stuff than the caustic soda, think it's the same pretty much but says its gentle, maybe it wont work idk, i have an old stem which i will test it on first