Spent an evening using duraglit or brasso stuff, the metal polish wadding that comes in a tin. Sad I know but the prop really shines now. Used a file to remove a couple of burrs and promptly lost a knot off the top speed
I use a product called Jasper, it's not very cost effevtive but does a fine Job.
However if Jasper wasn't around I'd probably use Petes method. there has to be some chemical way of removing the Oxidation. cos that's how it became oxidised in the first place.
I work with a bunch of chemical process engineers I'll ask one of them if they know.
Try a polishing mop on a drill with some polishing soap. Does a fine job on motorcycle parts. A dremel is just as good but takes a little longer. Takes abit of elbow grease but well worth it in the end. Polishing kits are available from most good tool suppliers and are reasonably cheap aswell.
I agree with Pete about 'tidying' the edge of the prop - it had a few blemishes so i lightly filed it - which has promptly reduced top speed noticably!! Bummer.
BTW if anyone has a surpless 22" stainless for a Yam v4 they want to sell drop me a line!
As for cleaning a friend aquired some 'Blo Loo' from work (yep he cleans toilets - but he's a good mate) which seams to clean all types of stainless very well - A-Frames, Props and Grab handles! Dunno where you get the stuff though!
