>what a can of WD40 does or indeed any oil or grease ?
Somewhat different - esp wrt wd40.
You can spray it on at the beginning of winter, it stays on, reapply it as/if necessary, then wash it off when the weather clears up/ following summer (two may not be coincident, of course !). If it's the stuff I'm thinking of, the particularly good thing about it in the case of motorcycles is that it's fine for engine casings, exhausts etc that get hot whereas grease/wax related stuff wouldn't stay on for long.The first year I rode my cbr over the winter I was horried with the state the unpainted/lacquered engine casings had reached when I came to remove the fairing lowers in the spring - I don't think ACF50 was available here 10 years ago...