Two accounts of a parallel therapy occur in Caraka's Compendium (Carakasaṃhitā). In one version, the patient akes Soma and spends six months naked in a greased barrel (6.1.4-7). In another, he enters a hut, as in Suśruta's account, but Soma is not involved. (See Roots, 2003: 76--8.)
In my discussion in Roots, I drew a parallel with the Aitareyabrāhmaṇa 1.3 in which a Soma ritual involving rebirth is described (the passage was kindly pointed out to me by David Pingree).
Now I have identified another passage that seems to be about the same ritual.
Pātañjalayogaśāstra (sūtras and bhāṣya)In the Pātañjalayogaśāstra (i.e., the Yoga Sutras and the Bhāṣya commentary, all by Patañjali), there is a sutra that lists the means by which super powers may be attained. Sutra 4.1 says:
super powers (siddhi) come from birth, drugs, mantras, asceticism, and meditative integration (samādhi)(janmauṣadhimantratapaḥsamādhijāḥ siddhayaḥ).Explaining this, Patañjali (not Vyāsa) says, in his Bhāṣya,
by using drugs means using rejuvenations (rasāyana) in the houses of the Asuras, and so on.No further explanation is given, and we are left to wonder what the "houses of the Asuras" might be.
(oṣadhibhir asurabhavaneṣu rasāyanenety evamādiḥ).
ŚaṅkaraThe commentator Śaṅkara, in his Vivaraṇa, expands on this passage in a significant way. He says (1952 edition, pp. 317-18):
oṣadhibhir asurabhavaneṣu rasāyanena somāmalakādibhakṣaṇena pūrvadehān apanayenaiva/The use of the word "soma" suggests that this commentator is putting together the idea of rasāyana entioned in the Bhāṣya with the specific rasāyana treatment described by Suśruta (and, more briefly, Caraka).
by means of drugs in the houses of the Asuras by elixir, by consuming Soma, emblic, and so on, by the complete removal of the previous bodies.
AsurabhavanaThe only place that Asurabhavana "home of the Asuras" is mentioned with any regularity is in the Pāli literature of the Buddhist Canon. For example, in the Mahā Suññata Sutta (Majjhimanikāya 122/3, tr. by Piya Tan; tr. by Thanissaro Bhikkhu), the Buddha is described worrying about the fact that worldly people live in too-crowded conditions for proper meditation. Asura bhavana is described as being ten-thousand yojanas wide, and is included in a listing of the various parts of the universe where living creatures live (and are crowded). Asurabhavana is therefore a geographical location in the Buddhist universe.
VācaspatimiśraExplaining Patañjali, the commentator Vācaspati (as so often) is guessing at the meaning on the basis of his general knowledge (e-edition at SARIT):
oṣadhisiddhim āha --- asurabhavaneṣv iti/ manuṣyo hi kutaś cin nimittād asurabhavanam upasaṃprāptaḥ kamanīyābhir asurakanyābhir upanītaṃ rasāyanam upayujyājarāmaraṇatvam anyāś ca siddhīr āsādayati/ ihaiva vā rasāyanopayogena yathā māṇḍavyo munī rasopayogād vindhyavāsīti/He states the super power of drugs: "in the houses of the Asuras." Because a human, for a certain reason, who has reached the house of an Asura, is served an elixir by the attractive Asura girls. After taking it, he achieves the state of never aging or dying, and other super powers. Alternatively, by taking elixirs in this actual world, like the sage Māṇḍavya took up residence in the Vindhya mountains through the use of elixirs.