I"m a little confused, check - a lot confused, about the suggestion that teaching women separate from men is "unethical". I don't see an ethics conflict in the least.
Guns, guitars, auto mechanics, needle point, I would not teach any subject the same if I had all men, all women, all teenagers, all Japanese speaking people, all gang bangers.
The primary job of any teacher in any subject is NOT to present a bunch of required material that students can regurgitate later. It's to figure out what makes each student "tick" and tailor the pedagogy to that set of parameters.
Teaching a group of 11 year olds how to change a flat tire would be totally different than teaching a group of 30 year olds. Likewise, teaching gun safety or marksmanship to a group of 25 year old women would be totally different than teaching a group of 25 year old men. There's no "ethics" question there, in any of the examples, including guns.
I suggest that the only time "unethical" comes to the surface is when you DO NOT account for the differences, backgounds, learning styles of women vs men, kids vs adults, teens vs people from mars etc.
Sgt Lumpy