For bikes we use washing up liquid, a pressure washer and a hell of a lot of elbow grease - the trick is to ensure that the track is brushed into extinction!
Having said that, I think it also depends on the drainage on the track. Mondello slopes a fair bit, so we can usually persuade it to run into the gutters.
The best option has to be the oil "nappies" which pretty much work in all conditions - but they're expensive and no-one wants to use them
