Can you provide an example from the scriptures of how Sai Baba's Udi helped someone with a specific problem?

Certainly. Chapter 35 recounts the experience of a gentleman from Bandra who was unable to sleep peacefully due to being tormented daily by nightmares of his deceased father. After all other efforts failed, he sought advice from a Sai devotee. The devotee, expressing great faith in Sai, gave him a small portion of Udi. He was instructed to apply a little to his head before sleeping, keep a packet under his pillow, and remember Shri Sai with devotion. As Chapter 35 describes, the devotee believed the Udi's natural tendency was to remove trouble. The gentleman followed this advice and was immediately able to fall into a deep sleep, free from the bad dreams that had plagued him.