One need only chant the Hare Krishna mahamantra. Everyone engaged in the practice of chanting the Hare Krishna mahamantra will be completely cleansed, from the core of his heart, and be saved from the cycle of birth and death.
Srimad Bhagavatam 7.6.1,
You just accept the holy name, then Nityananda Prabhu will be responsible for taking you across this material world.
Caitanya Mahaprabhu has recommended that everyone chant the Hare Krishna mantra just to cleanse the dust from the heart. If the dust of the heart is cleansed away, then one can actually understand the importance of the holy name.
Nectar of Devotion, Chapter 12,
Any person who is chanting the holy names of Krishna (Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare) in course of chanting without offenses feels some transcendental pleasure and very quickly becomes puriﬁed of all material contamination.
Bhagavat Gita 9.2,
The sound vibration of the Hare Krishna mantra, although presented in the ordinary alphabet, should not be taken as mundane or material.
Srimad bhagavatam 4.9.4,
The best means of spiritual realization is chanting the holy name of the Lord.
Bhagavad Gita 6.11-12,