Visuchika mantra is present in Yoga Vasistha and is given below in Sanskrit along with English translation
विषूचिकाभिधाना सा नाम्नाप्यन्यायबाधिका । तस्या मन्त्रः।
ॐह्रींह्रांरींरां विष्णुशक्तये नमः । ॐनमो भगवति विष्णुशक्तिमेनां ॐहरहर
नयनय पचपच मथमथ उत्सादय दूरेकुरु स्वाहा हिमवन्तं गच्छ जीव सः सः सः
चन्द्रमण्डलगतोऽसि स्वाहा । इति मन्त्री महामन्त्रं न्यस्य वामकरोदरे ।
मार्जयेदातुराकारं तेन हस्तेन संयुतः
The mantra runs thus said:—“There lives Karkati, the Rakshasi, in the north of the snowy mountain; her name is Visuchika, and it is for repelling her power that I repeat this mantra; Om, I bow to hring, hrang and ring, rang—the powers of Vishnu, and invoke the Vaishnavi powers to remove, destroy, root out, drive away this choleric pain, far beyond the Himalayas, and afar to the orb of the moon. Om (amen) and swaha (soho), be it so”. Let these lines be held on the left arm as an amulet.
[14, 69: Story of visuchika, 3: Utpatti khanda, Yoga Vasistha]
If a person is interested in chanting this mantra then is it mandatory to take initiation from an eligible guru (who already attain perfection in this mantra) or can chant it without any initiation?