Source: TW
śrī-śiva-mahā-purāṇe prathamāyāṃ vidyeśvarasaṃhitāyāṃ sādhyasādhanakhaṇḍe rudrākṣamahātmyavarṇanonāma pañcaviṃśo’dhyāyaḥ|
Śivamahāpurāṇa - Vidyeśvarasaṁhitā - 25th Adhyāya (Rudrākṣa-Māhātmya-Varṇana: Description of Rudrākṣa’s glory
paṃcabrahmabhir aṃgaśca trimālāṃ paṃcasapta ca | athavā mūlamaṃtreṇa sarvān akṣāṃs tu dhārayet || 42 || 42. With five mantras—Sadyojāta etc. three, five or seven garlands shall be worn. Or all beads shall be worn with the Mūla mantra[8].
madyaṃ māṃsaṃ tu laśunaṃ palāṇḍuṃ śigrumeva ca | śleṣmāṃtakaṃ viḍvarāhaṃ bhakṣaṇe varjayettataḥ || 43 ||
- He (the aforementioned wearer of Rudrākṣas and devotee of Śiva) shall refrain from eating meat, garlic, onion, red garlic, potherb, Śleṣmātaka, pig of rubbish and liquors.
valakṣaṃ rudrākṣaṃ dvijatanubhireveha vihitaṃ suraktaṃ kṣattrāṇāṃ pramuditam ume pītamasakṛt | tato vaiśyairdhāryaṃ pratidivasabhāvaśyakamaho tathā kṛṣṇaṃ śūdraiḥ śrutigaditamārgoyamagaje || 44 || 44. O Umā, daughter of the mountain, the white Rudrākṣa shall be worn by the brahmin, the red by the Kṣatriya, the yellow by the Vaiśya, the black by the Śūdra. This is the path indicated by the Veda.
Right between two verses which talk about Rudrākṣas (in a chapter that is overall dedicated to the greatness of Rudrākṣas) is a verse prohibiting the eating of meat, garlic, onion, etc. So, one can infer that this prohibition applies to the wearer of Rudrākṣas.
People are free to contend that they follow a Vidhi from the star Kolob and not the one in mainstream texts but they cannot call it a myth.
And Rudrākṣas cannot be worn at all times. Verse 95 of the Tamizh work Rudrākṣa-Viśiṣṭam of Śrī Nigamajñāna Sambandha Śivācārya states as follows (see image):
English translation as follows:
When lying down to rest, when doing mala-mūtra-visarjana, when doing maithuna/intercourse, when in pollution due to disease/sickness, birth and death, do not wear on the body that protection called kaṇḍi (tamizh term for Rudrākṣa).
shrI nigamaj~nAna sambandha shivAcArya
Rudrāksha jābāla upanishad says we can wear all times(sadākālam).
केयूरकटके सूत्रं
कुक्षिबन्धे विशेषतः । सुप्ते पीते सदाकालं
रुद्राक्षं धारयेन्नरः
- Firstly, many texts are called Upaniṣads; doesn’t make them Śruti.
- The Rudrākṣajabalopaniṣat shares several ślokas with the Vīraśaiva recension of Makuṭāgama (which is actually a Saiddhāntika Āgama); it appears that this Upaniṣad may have originally been prepared by the Vīraśaivas/Kālāmukhas.
- Vīraśaivas came up with concept of an Iṣṭaliṅga that is to be worn at all times. It would not be surprising that they came up with a similar idea for Rudrākṣas. If someone is initiated into that Mārga, they may follow it.
- However, the Siddhānta teaches a more restrictive approach, according with the status of the Rudrākṣa.