Snāna is as important to a upāsaka of Tantra as to any other ritualist of śrauta or smārta streams. It is said:
स्नानमुख्याः क्रिया सर्वाः स्नानं च दैवते भवेत् |
Rituals performed without a ritualistic bath do not yield the desired fruit.
When does one take a bath?
प्रातःकाले च मध्याह्ने सायाह्ने स्तोत्रपाठके |
यदा यदा मनोग्लानिस्तदैव स्नानमाचरेत् ||
Needless to say, one should take a bath thrice before observing the three sandhyās (vadikī and/or tāntrikī), as also before undertaking the recitation of hymns like Durgā Saptaśatī, Lalitā Sahasranāma, etc. Whenever one encounters disturbing thoughts, or when one utters falsity or abuse, one should resort to mantrasnāna by mentally reciting the Pañcadaśī or ṣōḍaśī mahāmantra (in the case of śrīvidyā) or the mantra of Pañcakrama Kālikā (Dakṣiṇā, Guhyā, Kāmakalā, Chintāmaṇi or Kālasaṅkarṣaṇa Kālikā, in the case of Kālīkula). The advice is to mentally recite the mantra and not utter it aloud as it is said in śrīkrama:
विद्योच्चारं तु यः कुर्यादस्नातः कृतभोजनः |
तस्य विद्या भवेन्नष्टा रौरवं नरकं व्रजेत् |
तस्य नाशो भवेद्देवि विद्या दग्धा भवेद्द्रुवम् ||
One who utters the sacred mūlavidyā (aloud) without having purified himself through a prescribed ritualistic bath or after having consumed food, loses his vidyā. If one utters the vidyā in a state of impurity, such an ignorant person faces destruction. His mantra becomes dagdha, and hence incapable of granting siddhi.
It is to be noted that the prohibition here is only in terms of verbal (vācika or upāmśu) utterance of the mūlavidyā (Pañcadaśī or ṣōḍaśī or one’s mūla-mantra). By other pramāṇas dealing with mantrasnāna as also the verse in Rudrayāmala (śucirvāpyaśucirvāpi, etc.), it can be safely concluded that no such restriction applies to the mental (mānasika) recitation of the mūlavidyā.
The Tantras of Krama (śrī and Kālī) speak of five kinds of snāna (bath):
1. Vāruṇa
2. Nābhasa
3. Bhasmaja
4. Taijasa
5. Daivata
The deities for these five kinds of baths (invoked during the saṅkalpa for each of the five kinds of ritual baths) are Brahmā and Parā, Viṣṇu and Parātītā, Rudra and Tatparā, īśvara and Chitparā, Sadāśiva and Chitaparātītā.
The first kind of snāna, Vāruṇa, is of two kinds: Vaidika and Tāntrika. The Vaidika snāna is performed as taught in svaśākhā and tāntrika snāna based on the kalpa followed in one’s sampradāya.
Nābhasa snāna employs the mālāmantra of Tripurasundarī for purification of the subtle energy body of the upāsaka, whose exterior is already purified through Vāruṇa snāna. Based on śuddha, namō, svāhā, tarpaṇa and jayānta as well as śiva, śakti and śiva-śakti mithuna, there are fifteen mālāmantras, one for each tithi of the month. The upāsaka contemplates on the mālā corresponding to the current tithi within his body invoking the raśmis in the appropriate places, ranging from the adhaḥ sahasrāra to the ūrdhva sahasrāra. By such an act of raśmi saṅkalana, the upāsaka earns the merit of having bathed in sacred tīrthas including the Ganges, during prescribed r̥tus and auspicious moments of time. The result of such raśmi saṅkalana is the appearance of the śāmbhava-śarīra of the upāsaka. The snāna is concluded through the laya of all raśmis within the Mahāpādukā of mula-dēvatā Mahātripurasundarī in the Brahmarandhra.
The next variety of snāna is called Bhasmaja as it involves the use of the sacred ash or bhasma. Bhasma is considered sacred as it represents three purifying tattvas: Agni or fire, jala or water, and sthala or earth. Agni and sthala combine to form the sacred ash while it is mixed with jala to be used for application. The bhasma is sanctified by the mantras of pañca-śambhus (īśānādi śaiva r̥kpañcaka), Mālinī mantra, Sūrya mantra, śrīvidyā, etc. and applied all over the body to accomplish bhasma snāna.
The next method of snāna is called Taijasa as it involves the unification of three kinds of energies or tejas: of the Guru, of the mantra, and the mūla-dēvatā. The Guru is invoked through the Mahāpādukā mantra in the sahasrāra, the mūlamantra in the throat, and the muladēvatā Mahātripurasundarī in the heart through dhyāna and daśamudrā. The three are merged within the Guru in the sahasrāra and unity of the self with this formless, timeless, nameless eternal energy is experienced, the result of which is the flooding of bliss through one’s entire being. Such a kind of taijasa snāna prepares one for dēvatā sākṣātkāra.
The final variety of snāna is termed Daivata. The upāsaka visualizes the mūla dēvatā within his body, from the adhaḥ sahasrāra to the ūrdhva sahasrāra. The face of the dēvatā is seen as one’s own face, limbs as one’s own limbs and so on – so as to attain complete tādātmya or unity with the deity. The three sacred rivers Gaṅgā, Yamunā and Sarasvatī are invoked within the three nāḍīs: iḍā, piṅgalā, and suṣumnā. The Gurumaṇḍala is invoked in the sahasrāra, the aṅga, pratyaṅga, upāṅga dēvatās in the ājñā chakra and the āvaraṇa dēvatās of śrīcakra within the Lambikā padma.
By undertaking these five kinds of snāna, the upāsaka progresses rapidly on the path of the mantra siddhi. For śrīvidyā, one is advised to observe five sandhyās: prātaḥ, madhyāhna, sāyam, and turīya. The same is true for Pañcakrama Kālikā as well. Tārā, Bhuvanēśvarī, and Chinnamastā command the observance of three sandhyās. These snāna are to be accomplished before the observance of every sandhyā.