The Rishi Agasthya's One of the Tantric Practice in Bengal is considered as Baul. It is also significant how the secrets of Atharva Veda is still being practiced by Baul Sadhaks where ancient wisdom of Ayurveda is there.
In the Tantric culture the Ayurveda is little bit different. It comes from Guru Matsyendranath and Guru Gorakshnath tradition, where different herbs along with specific mantra is there. It is not just on Bata, Pitta and Kafa. Total inner system is incorporated in this very ancient science.
In the Baul sadhana the basic four tattvas are very strongly experimented and realised. Very few sects of Indian Spirituality has this knowledge.
Sadhguru learnt this technique and the entire Baul sadhana from his Guru and his father Avdhoot Atmananda from his very child hood. The Nath Yogi Avdhoot Atmananda has strong bonding with legendary Nabani Das Baul and Sanatan Gosain or Sanatan Das Baul.In the Year 1960 when Atmananda became Avdhoot he started his journey from Garh Jungle, in Burdwan West Bengal. During that time he was closely associated with several sadhaks from Tantric tradition, Nath tradition and Baul. In the year 1980 the secret yogi Atmananda took his son to introduce him among the sadhaks who were still alive at that time. Out of them Sanatan Gosain or Sanatan Das Baul, Nitai Khyapa, Kanai Das Baul, at Tarapeeth, Nakshatra Das Baul, Sadhan Das Bairagya, and many others are there.