Probably washes away but WD-40 works for my bare frames until I paint them:
This has been "bare" for 6 months, granted it was ridden in the rain but it was subjected to high humidity during the summer months. Only applied WD-40 twice. My Tandem is in the same state and is used more often:
'[IMG]108_PaTrek by superissimo_83, on Flickr[/IMG]