Could you recount the entire story of Kaka Mahajani's friend, from his skepticism to his experience in Shirdi?

Certainly. Chapter 35 narrates the story of a friend of Kaka Mahajani who was initially a skeptic, averse to idol worship. He agreed to go to Shirdi out of "clinical curiosity" but on two conditions: he would not bow his head, nor would he offer Dakshina. Upon their arrival at the mosque, Sai Baba addressed the friend in a tone that was an exact imitation of the friend's deceased father. This uncanny experience deeply moved him, causing him to forget his resolve and bow at Baba's feet. Later, when it came to Dakshina, Baba pointedly asked Kaka Mahajani for money on two separate occasions but completely ignored the friend. This act of not asking for Dakshina from the one who had sworn not to give it left the friend feeling restless and thoughtful.