Chanting wisdom.

https://krishna.com/some-scriptural-references-hare-krishna-maha-mantra

“By chanting the maha-mantra, one becomes quickly purified from all sins accumulated due to rejecting all of one’s duties in our past lives. Thus the Hare Krishna maha-mantra, is the only means, the only means, the only means of thoroughly and immediately purifying oneself in Kali-yuga. Thus ends the Kali-santarana Upanishad.”

Srila Prabhupada tried to introduce 64 rounds in ISKCON but some devotees where bargaining with Srila Prabhupada so he reduced it to facilitate his neophyte disciples,thus it has become the minimum standard ,Srila Prabhupada encouraged more chanting.

https://nimaipandit.ning.com/profiles/blogs/kali-santarana-upanisad-and