One who chants the holy name of the Lord is immediately freed from the reactions of unlimited sins, even if he chants indirectly [to indicate something else], jokingly, for musical entertainment, or even neglectfully. This is accepted by all the learned scholars of the scriptures.
Srimad Bhagavatam 6.2.14,
The ultimate goal of Bhakti is to get Krishna and we get it by taking shelter of the holy name.
It is said, kali-kale nama-rupe krishna-avatara: Krishna descends in this Kali-yuga in the form of His holy name — Hare Krishna, Hare Rama.
Srimad Bhagavatam 9.10.53,
The Hare Krishna mahamantra is also a prayer, for a prayer addresses the Supreme Personality of Godhead by His name and invokes good fortune by petitioning the Lord to allow one to engage in His devotional service.
Srimad Bhagavatam 4.24.69,
Of sacriﬁces I am the chanting of the holy names [japa].
Bhagavat Gita 10.25
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,