What is the ruling on opening a henna salon for women in a non-Islamic country, frequented by non-Muslim women?

It is recommended for a married woman to dye her hands and feet with henna, while it is disliked for an unmarried woman to do so. It is permissible for a woman to apply henna for others, as long as they are not among those who adorn themselves with it for illicit relationships or display it in front of strange men.