According to the teachings in Chapter 16, what is the most effective action a disciple can take for their own spiritual benefit?

The most effective action for a disciple, as detailed in Chapter 16, is complete and humble surrender to the Sadguru. The text explicitly states, "What should a disciple do? He should simply surrender himself to the Sadguru." This is because the disciple often does not know their own pitfalls or weaknesses, but the Guru does and provides the remedy unknowingly. The chapter asserts that by serving the Guru with faith, the servant can attain union with Brahman (Sayujya), and that all other means will fail. Therefore, placing firm faith at His feet and surrendering the ego is presented as the ultimate path to spiritual liberation.