This purification, how it is done? Now, yaḥ smaret, "One who remembers," puṇḍarīkākṣaṁ, "Kṛṣṇa, always," sa bāhya, means "externally," and abhyantaram, "internally," śuci, "purified." So if you chant Hare Kṛṣṇa always, either loudly or silently or within yourself, mind, if you chant, so there is no question of impurification. It is . . . you remain always in, what is called, antiseptic stage, or prophylactic stage. Purification is there simply by remembering Kṛṣṇa. Yaḥ smaret puṇḍarīkākṣaṁ sa bāhyābhyantaraḥ śuciḥ (Garuḍa Purāṇa).
There is another verse. The purport of that verse is that simply by pronouncing this transcendental vibration, one becomes so purified that immediately he becomes eligible to operate sacrificial, ritualistic ceremonies. Now, sacrificial, ritualistic ceremonies, in the Vedas, priestly, that is . . . that work is, I mean to say, allotted to the brahmin class.
Now Jīva Gosvāmī has discussed this verse in this way, that "Even a caṇḍāla, a person born in the family of dog-eaters, if he chants the holy name of the Lord, he becomes so purified that immediately he becomes eligible to operate sacrificial, ritualistic ceremony."