yes. However, despite the fact that I use it, my internal grammar Nazi dies a little every time I say it - "their" is third-person, not second-person. I use it, but I'm not comfortable with it. Just as often I will simply "assume" masculine and use "he" and "his", even when gender is unknown, thanks to the French grammar rules of a group being masculine if at least one in the group is masculine.
Since learning French I've begun to use "one" and "one's" as gender-neutral second-person pronouns, but old habits die hard and "they" and "their" still slip out as second-person.
Since learning French I've begun to use "one" and "one's" as gender-neutral second-person pronouns, but old habits die hard and "they" and "their" still slip out as second-person.