I am asking you a very personal question, there may be instances where women had been unchaste before knowing /am following KC due to different reasons or their own mistakes. How does KC teach them to be chaste? This thought just came to my mind as there are women from different background?

there were Devotees who even did worse when they were not Devotees yet. But knowing that it was wrong they stopped sinful activities but started to chant. And Krishna is All Merciful. Nowadays those people are saints. We are not this body. Body changes every 7 years. And chanting process is so powerful that can remove all sins. As like Valmiki Muni was a very great sinner but by uttering the Names of Rama cleansed his heart fully.

But knowing to commit sins is considered as an offense. Which is very dangerous to spiritual life.

Chasity is that we follow strictly 4 regulative principles and chant 16 rounds.

And build our life according to Vaishnava etiquette.

(http://vaishnavaetiquette.com/)