Various techniques explained by the Yogis to achieve Ajapa are as follows:
Through Kumbhak (Retention), one has to achieve a state of no Rechak (exhalation) and no Poorak (inhalation).
In it balance of Pran and Apan is achieved in the navel.
From Sahsradal nectar is continuously flowing. In the agitated state of pran opportunity to drink the nectar arises, one should not drink it but rather perform abhishek of the shinning Mahadev in the Manipur Chakra, chanting Hamsa mantra.
This is spiritual solar eclipse.
Adept Yogis perform Sakshatkaar of Bindu (both Sakal i.e. with vibration and Nishkal i.e. without vibration) in their body itself.
Pran keeps rotating in between Ida and Pingla. These are popular as Uttrayan and Dakshinayan. Entry of pran in Mooladhar is 1st Vishuv and entry of pran in Sahasrar is 2nd Vishuv. Vishuv represents same state of balance when day and night are equal. In body also balance of these two bindus occur. Hence the name Vishuv. Yogis duty is to turn ‘Hamsa’ into ‘Soham’. This is the SECRET of Yoga. During this process Mudras happen on their own. This mudra is called Chin Mudra. Its also called Shambhavi Mudra or Khechari.
To ever drown in Soham-asmi dhyan is Pratayaksha Yoga. Pran vayu enters Kundlini from Pingla side. This is called spiritual Solar eclipse.
As per Upnishads, Hamsa yoga gives knowledge of Atma. In it following procedure is followed,
Sit in Sidhasan, close anus and perform Poorak.
Depending upon individual capacity, by contraction raise the pran collected there as per earlier step.
Then establish balance in Pran and Apan. Raise the fire element from the Mooladhar and join it with Pran and Apan. Kundlini will awaken with it open Brahm Granthi (knot).
Till its open one can not enter Mooladhar and pierce various chakras afterwards.
Afetr entering it, meditate on the central point of it, with the dhyan upward movement is achieved.
Then circumambulate three times and raise to raise energy to the next chakra piercing from below.
Vishnu Granthi is below Anahat and before Ajna Chakra, Rudra Granthi is pierced.
Anahat entry entails turiya dhyan in central bindu and Savikalp Samadhi is attained here.
When one is approaching Vishudhi chakra two balls are seen. Following the middle path enter the Vishudhi. Here pran is neutralized. After this Rudra Granthi is pierced before entering Ajna Chakra in the forehead.
Then turiya dhyan in its bindu is performed. If yogi can reach this state, then capacity to join Sun, Moon and Fire is generated. Then difference in the effulgence of these three states disappear. All of them join together to give rise great effulgence or Mahatej and qualification to taste the nectar of Sahasrar arises. Becoming free of old age and death, the yogi enters Brahmrandhra. Turi darshan is attained and 4th stage is realized. That which has got three matras over it is called Turiya. While entering turiya-turiya these matras also disappear one becomes the real witness for a prolonged time and not a momentary. In turiya some grossness remains but in Turiya-turiya there is no grossness at all, it is paramhamsa state and is beyond explanation.
Ajapa is mantra of the soul or atma. In the three states of waking, sleeping and dreaming, jivatma is different from Paramatma. It establishes Mahatattva. This mantras Rishi is Brhma; Chand is Gayatri; Devta is Atma; Shakti is ‘Sa’; Seed is ‘Ha’. This mantra has two parts, one part represents Shakti while other part represents beej.
Aham or Ego represents Shiva, it lightens up Paramshiv. This Shiva creates another force opposing its own self which is other than him, that is called Shakti or prakriti and is represented by ‘Sa’ while Purusha or male aspect is represented by ‘Ha’.
In the lotus of the heart, Anahat Chakra, four petals out of the ten have no connection to our breath. Jiva endowed with pran and apan is called Hamsa. This Hamsa moves continuosly in other 8 petals of Anahat. All the emotions rising in the mind are stored in these petals. Which ever petal is touched by the Hamsa or Prana at any moment, that particular emotion arises in the person. From the Ishan direction (North-East) the petal petals are counted.
When Pran is moving in the petals mind gets agitated or outward moving; when it moves to the centre it becomes one pointed and leaves all the outward thoughts. It increases emotion of renunciation When it moves in the keshas ego is totally annihilated. When it enters centre ego is half raised representing dreaming state. When it enters central bindu it is deep sleep. When this Shunya is also transcended then there is no connection with the lotus, that state is called Turiya. This is the state of the observer or witness. Before Hamsa is Naad in which mind looses itself slowly and slowly. Its highest state is Unmani (beyond mind). This is turiyateet (beyond Turiya). It has two states, Sa-Adhishthan(with support) and Nir-Adhishthan(without support). In the first state physical body is kept but one does not feel the three pains; while in the second the physical body also is not kept. This is the non-dual state of Brahma. S-kaar is Tvam(You) and Ha-kaar is Tat(That). Joining of the two is referred to as Tat Tvam Asi (one of the main great statements referred in the scriptures).
Imagination is dharana of mind and it should be renounced for ever. By controlling pran, Ensnared pran is converted in to Free pran. By this method, the outer thoughts and body sanskaar are annihilated……………..(translated from Bhatiya Sanskriti and Sadhana by Gopinath Kavirajji).