Most of the gender unspecific (did I just invent a word there?) are from professions that were originally limited to one gender. How could a female pilot use a COCK pit or a JOYSTICK? Both these terms were coined with specific sexual intent!
Almost all the terms are male specific, the only one that I can think of as being female specific is Nurse.
One de-sexed job description that I do like is Chair instead of Chirman (or woman) as this implies that the person doing the job is almost an object or tool and therefore impartial!