Hi, Mark.
Sailing a small boat in a STEADY Force 6 is ok if you don't mind getting wet.
A gusty wind is a different matter. Just how "adventurous" or "sensible" it is depends on circumstances like:
a/ the sea state (breaking waves are only fun on a sailboard)
b/ the type of boat,
c/ your level of competence (not "confidence")
d/ ..and what sort of support you've got.
Being a fully paid up member of the Lily Livered Society (Not heard of us? We have a badge that we wear with pride - a wide yellow stripe running down the back of our oilskins.) I no longer feel any peer pressure to sail when I don't feel like it and my simple rule of thumb - "If it looks bad from here it's probably a lot worse when you get out there!" - has served me well.
Other weather-related rules:-
" If you think you might need to reef, you should have done it 5 minutes ago!"
" I'm supposed to be doing this for fun, damn it!"
and my favourite catch-all:-
" Any fool can be uncomfortable!"
Let the Gung-Ho types and their weak-minded acolytes go out in a gale and return, glowing with pride and a sense of achievement, bless 'em. If they need that stuff to boost their egos and are putting no-one else but the RNLI at risk (and the mortgage and funeral expenses are taken care of), good luck to 'em! I did all that nonsense when I was in short trousers and grew out of it before I started shaving. (e.g. At the age of 9, hoping to impress Rosalie Tompkinson with my resemblance to Tarzan, I threw myself out of a tree. Her laughter hurt more than the twisted knee, or the clip round the ear I got at home. Not everyone has had my advantages, though, so I try to make allowances.)
Dirty Sails? (..finally getting to the point....)
I have used this stuff (See picture ) intended for canvas with no obvious ill effects but I did hose them down thoroughly afterwards.
Bathroom mould remover works - with the same precaution.
Rust marks have to stay - or use some pretty vicious chemicals.
Biggest mistake I made was to wash them on the drive. They picked up more dirt than I washed off! Had to rinse them again, this time on a large tarp spread underneath them.
The whole business was a pain in the posterior so I've never repeated the operation. I remove salt before packing them away, by hoisting them in the rain or spraying them with a hose. Then you have to dry them!