Krishna conscious preaching is not about telling others what to do. Of course if someone wants personal guidance, that is another thing. But generally speaking, preaching mostly entails glorifying Krishna. When the listener hears the non duplicitous glorification of Krishna, automatically the listener will cultivate a sense of desire, and yearning to know more eventually leading to faith in Krishna. This faith will eventually make the listener Krishna conscious and also give up bad material habits.
Once Srila Prabhupada wrote a letter to a college preacher (do not remember the exact reference), he said preach in such a way that the students will realize on their own what to do and what not to do. Prabhupada also said to the college preacher that even if they accept one aspect of the philosophy which is "we are not bodies but spirit souls" will be deemed success from a preaching perspective.
So we can take a cue from the above letter (which I paraphrased) that today every one is like a college student in the sense every one is very informed through the internet and the computer. Naturally every one is skeptical in the beginning just as students are trained to do in college. So if we get an opportunity to speak about Krishna, using Prabhupada logic, we can speak in such a way that the listener will realize his material conditioning and want to become Krishna conscious.
Although I have not closely associated with temple devotees of Chowpatty, I believe H.H.Radhanath Maharaj uses his realization, speaking abilities simply to glorify Krishna in his lectures and this genuine glorification has created the huge congregation in Mumbai. In my opinion & experience thus far, Indians are tough to preach to and if Maharaj can convince them of Krishna, then surely it is by his narrations of unalloyed glory of the Supreme Absolute Truth Krishna.