The devout recite selections from Purāṇas such as Harivamśa, Dēvī Bhāgavata Mahāpurāṇa, Viṣṇu Bhāgavata upapurāṇa, Garuḍa Purāṇa etc. However, these are not recited as Mālāmantras like Srī Durgā Saptaśatī. Saptaśatī belongs to a totally different genre.
Dēvī Kavaca, Kīlaka, Gurukīlaka, etc., chanted traditionally as part of Saptaśatī japa are also not a part of Mārkaṇḍēya Purāṇa. The krama followed, wherein Saptaśatī is not merely a Purāṇic hymn inspiring devotion, but instead a potent Mālāmantra, is essentially Tāntric and derived from Tantras such as Rudrayāmaḷa, Skandayāmaḷa, ḍamara, Kātyāyanī, and Vārāhī Tantra. Thus, technically, one can recite the Saptaśatī without Kavacādi traya, Nyāsas, Navārṇa japa, etc., as a potent stotra from the Purāṇa – but not as a Mālāmantra. According to a pramāṇa quoted from the Kātyāyanī Tantra by a commentator on Saptaśatī: ‘The Māhātmya of Chaṇḍikā recited without Navārṇa sampuṭa is like eating a mango seed with the hope of growing a mango tree and wishing to consume the fruit from that impossible tree’. Other Tantras also provide ample warnings about Yoginīśāpa.
Devotees who do not understand the inner significance of Srī Durgā Saptaśatī need to necessarily study the scholarly commentaries on this work. For example, Srī Bhāskararāya Makhīndra, in his aptly named commentary Guptavatī, derives the Navārṇa mantra from the first three ślōkas of Saptaśatī. Similarly, Navārṇa mantra and its echoes can be observed throughout Saptaśatī. Thus, considering all such pramāṇa from the Tantras, as well as sampradāya traced back to eminent upāsakas like Srī Bhāskararāya and Nāgōjī Bhaṭṭa, it is safe to say that without the japa of Navārṇa mantra, Saptaśatī cannot be considered as a Mālāmantra. There is also an explicit statement in the Vārāhī Tantra that Saptaśatī pārāyaṇa should not be attempted without the Navārṇa dīkṣā.
The elevation of Saptaśatī from a Stotra to a Mālāmantra happens by associating it with the Navārṇa mahāmantra, which is described as Trailōkyaḍāmara and Kalipraśasta mantra. It is through the agency of this mahāmantra that one can access the immense potential of Saptaśatī. This is similar to the relationship between Srī Lalitā Sahasranāma and Srīvidyā Mahāmantra. Such a relationship does not exist for the recitation of Dēvī Bhāgavata, Harivamśa, Rāmāyaṇa, etc. Without the agency of the Mulamantra, which in this case is the Navārṇa, the sādhaka only derives an iota of the limitless potential of these two Hymns. Additionally, śāpōddhāra and utkīlana vidhāna for Saptaśatī are derived from the Navārṇa kalpa.
Saptaśatī and Navārṇa are related in two ways. While doing the puraścaraṇa of Durgā Saptashatī as a Mālāmantra, chanting Navārṇa as a necessary aṅga is the first aspect. The pramāṇa for this are ḍāmara and Skandayāmaḷa Tantras. The other aspect is the recitation of Saptaśatī as a part of Navārṇa puraścaraṇa. The pramāṇas for this case are Rudrayāmḷa, Kātyāyanī and Vārāhī Tantras. In the first case, Navārṇa is an absolute aṅga of Saptaśatī. In the second case, the primary importance is awarded to Navārṇa. Thus considering the nyāya of anga and angi, Navārṇa becomes an absolute necessity in either case, and the only way to obtain this mahāmantra is from Sadguru. For those that do not have the required dīkṣā, there are numerous other stotras and sahasranāma stavas which can be recited without such restrictions or pre-requisites.
A Durgā temple was opened in someplace in āndhradēśa and the temple committee appointed a priest. After a few months, the priest went with prasāda to H H Srī Chandraśēkhara Bhāratī and said, ‘Your Holiness, I have recited Saptaśatī 108 times and brought you prasāda. Please accept it and bless me’. Mahāsvāmigaḷ gazed at him for a second and said, ‘How is your daughter” The startled Brāhmaṇa answered, ‘She is unwell these days. She is suffering from epileptic fits’. Mahāsvāmigaḷ immediately said, ‘Without Navākṣarī you have been chanting Saptaśatī. This is like banging your head on an iron box to open it. You have been sent here by Sharadāmbā only because of your Bhakti. Please receive the mantra as per the proper means from our administrator Nanjanagūḍu Srīkaṇṭha Shastrī, perform lakṣajapa and then resume reciting Saptaśatī. Without a Guru, don’t try experimenting with maṇi, mantra, and auṣadha”. The importance of pronunciation need not be reiterated here as the story of ‘bhāryāṁ bhakṣatu bhairavī’ is well known to most. As I listed elsewhere, there are pūrva and uttarāṅgas of Navārṇa mahāmantra and these need to be learnt from Sadguru along with the meaning of the Navārṇa discussed in the Dēvyatharvaśīrṣa.