Chaitanya Mahaprabhu has recommended that everyone should 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.
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,
Cleanliness is essential for making advancement in spiritual life. There are two kinds of cleanliness: external and internal. External cleanliness means taking a bath, but for internal cleanliness one has to think of Krishna always and chant Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare. This process cleans the accumulated dust of past karma from the mind.
Bhagavad Gita 13.8-12,
When we hear about the Lord, we should hear with a spirit to serve the Lord. When we chant his names, we should chant so that He is pleased to hear us chanting. That is the beauty of life, the real art of living.
Of sacriﬁces I am the chanting of the holy names [japa].
Bhagavat Gita 10.25
Even the very sound of the holy name of Lord Krishna or Rama can at once surcharge the atmosphere spiritually.