Sailningdog Yes that's one of my fallbacks. Alternatively to get them directly from the UK over the Internet and courier.
True Blue: The Zenith (whihch I have) is also around $23:00 direct from the supplier plus courier costs. This is probably the way to go. In the mean time I'll try something neutral like a non petroleum based 'oil' and see if it makes any impression. Thanks to all for the time.