Try waxoil
I did last year. Got aerosol - 2 cans was enough - and sprayed everything metal, including engine, downpipes and exhaust, except tank and brake discs.
Learnings:
1) Make sure you check the colour - it comes in clear and black (looks like treacle toffee) - I didn't and got one of each
2) After a few weeks the whole thing looks like sh*t anyway so it doesn't really matter
3) Don't worry about the engine, exhaust and other hot bits - the first time you pull away you look like something out of a Hammer Horror movie with clouds of smoke all around - so make sure you have an appreciative audience
4) I didn't wash or hose down all through winter - from Nov to mid March - except to clean screen and lights
5) I used Gunk to remove - not a jet wash - jet wash can (did) remove paint from fork brace
6) The downpipes may take a bit of polishing up
7) Re learn the joys of washing and polishing every week
8) Oh yeah, the important bit, no problems with corrosion, rust or white fluffy deposits
Right that's my 2p worth. I'm off to Valencia for the GP, and a last look at some sunshine
