In my Swan 68, I have a couple of heads but for the ladies I'm planning
to install a bidet. A first class stainless steel bidet at that:
http://img.nauticexpo.com/images_ne/photo-g/94175.jpg

Now, I've never used a bidet but my understanding is it's not a head.
Rather one uses the head first to do one's business and then uses the
bidet for a thorough clean up of the soiled bottom or vagina.

From a discharging of waste standpoint is the gray water coming out of a
bidet considered sewage? Or is it gray water that can be disposed of
directly overboard?

I hesitate to plumb the bidet into the holding tank because I know how
much water women are prone to use. But if it's illegal to plumb it
straight overboard then I guess I shall have to do so.

Wilbur Hubbard