How was the Udi used by the man from Bandra to stop his nightmares?

The story of the gentleman from Bandra, found in Chapter 35, provides a clear method for using Udi to combat nightmares. After all other efforts failed to bring him peaceful sleep, a Sai devotee advised him on a specific remedy. The instructions were to take a small portion of the Udi and apply a little of it to his head when going to sleep. Additionally, he was told to tie some Udi in a packet and keep it under his pillow. Crucially, he was also to remember Shri Sai in his mind and maintain devotion in his heart. Following this practice immediately removed his troubles, and the bad dreams were erased.