Haridasa Thakura never wanted to enjoy the prostitute, but he tricked her to deliver her by giving her a chance to hear the holy name of the Lord while he chanted. Pure devotees chant the Hare Krsna mantra, and simply by hearing this chanting from a purified transcendental person, one is purified of all sinful activities, no matter how lowborn or fallen one may be. As soon as one is thus completely free from the reactions of sinful activities, he is eligible to render devotional service to the Lord. This is the process for engaging the fallen souls in devotional service. As Lord Krsna says in Bhagavad-gita (7.28):

"Persons who have acted piously in previous lives and in this life, whose sinful actions are completely eradicated and who are freed from the duality of delusion, engage themselves in My service with determination."