Moonflower wrote:

Oh, thanks. Much appreciated help. Though I wouldn't mind opening the
window on the bath, I try to keep it shut coz I have a lot of peeping
toms. :-) Not the up-close type, but the ones with scopes and
binoculars and such.

Don't ask me how I know. It's fun frustrating them from time to time.

Hmmm,
If you don't control the moisture in the bath room all your hard work is
wasted. You'll never solve the problem.