How does the story of Narayanrao's friend and the scorpion sting illustrate the power of belief when using Baba's Udi, or even a substitute for it?

This incident, narrated in Chapter 33, powerfully illustrates that the devotee's belief is a critical component in the efficacy of sacred objects. When Narayanrao's friend was stung, no actual Udi from Baba's dhuni was available. Instead, Narayanrao used the ash from burnt incense sticks found beneath Baba's picture. The crucial detail is that he "considered it as Udi in that moment" and applied it with sincere prayer and by chanting Sai's name. The immediate healing proved that the ash worked because of the immense faith invested in it. The text confirms this by stating, "This was only the Vibhuti of incense sticks; it was applied to the suffering one. But being considered as Udi from the path, such was the experience manifested."