petrol cleans these white-coated guardrail wires instantly. But really, they are a bit rubbish imho - stripping the white plastic off reveals these to be skanky not-quite-stainless steel like the wire ones which iis why they are fited - cos cheaper material/metal. Get the wires ones, then don't need to cleanem ever, heehee.
MER polish will clean the stanchions of rust stains, and will then leave a protective film on the stainless to help prevent re-occurrence of the stains.
yeah, lend some mug the boat for a weekend and say oh and if you could just give it a once over - and i am very particular about the stanchions but have loaned the boat to lots of peeps recebntly so not sure what they look like but they actually only a year old. I bet they wd look failry decent then.