I live right on the east coast of England, and in winter the salty spray and atmosphere from the North Sea gets everywhere. I've never seen insulators being washed though, and I've lived here 4 yrs.
I've also been led to believe that 100% pure deionized water is a very poor conductor, although my chemistry is so rusty that I couldn't start to figure out why without reading a few books.
Anyway, whatever the chemistry says, I'd be far too much of a coward to want to play chicken with 11kV+.
