Hi David!
We've got a pair of BeoVox 1 in the ceiling in our bathroom. To get a maximum performance we also installed the wooden boxes, from B&O, specially made for BeoVox 1 (but it's only the speakers that are visible). The Beolink Passive is placed in a wardrobe in the basement right under the bathroom, with the eye placed above the light button in bathroom. One of the speakers are placed just above the shower without any problems at all (and my wife and kids really like to shower hot and long).
The sound of the speakers are excellent, even at really loud volume. Recommended!
In the laundry room we've got a BeoLab 2000, with out any problems. But it's placed the opposite corner of the washing macine and air dryer. So I don't think there's high humidity there, so I can't say if that will stand your humidity. But if the CX could do it, I think the 2000 would do it as well.
Beovision LX5500, BeoCord V6000, BeoSound 9000, BeoLab 8000, BeoLab 3500, BeoLab 2000, BeoVox1, BeoCom 6000, Form1, LightControl 1