I thnik, even women are allowed to enter through this gate during those times.
The restriction imposed is only during Mandla Kalam if I am not wrong. This restriction comes because of women's inability to compelte 41 days vrat, as her menstrual cycle intervene in between. Try to understand that nobody has said that women are impure or that they are interior. It is just a custom as in Attukal where males are prohibted.
As regards PURITY is concerned, once you wear that mala on Vrichit 1, you virtually lose your individual identity. YOu are then onwards for the next 41 days known as 'swamy' or 'ayyappa' Devotees who undertakes penance for going to Sabarimala greet always with Swami sharanam, and they address each other as swamy only. Even a rougue, once he decides to go to Sabarimala, mend his ways. He is not supoosed to tell lie, he will not quareel with anybody, he will not harm anobody with thoughts and action. You should visit the shrrine only with a pure mind. All real devotes still observe these rules strictly - I am talking about real deovtees and not those who are going there as if they are out for some picnic.