Heart is cleansed means you understand that you are not this material body. That is cleansing of heart. Everything is going on on this misunderstanding that "I am this body." "I am Indian," "I am American," "I am this," "I am that." This is the grossest type of misunderstanding. So that becomes clear. Then you stand on your own position, brahma-bhūtaḥ prasannātmā na śocati na kāṅkṣati (BG 18.54). There are so many things we'll gradually follow. Therefore if we chant Kṛṣṇa's name without any offense... There are ten kinds of offenses—but in the beginning, even there is offense, you go on chanting and gradually, as your heart will be cleansed... That is explained by Śrī Caitanya Mahāprabhu.
- ceto-darpaṇa-mārjanaṁ bhava-mahā-dāvāgni-nirvāpanaṁ
- śreyaḥ-kairava-candrikā-vitaraṇaṁ vidyā-vadhū-jīvanam
- ānandāmbudhi-vardhanaṁ prati-padaṁ pūrṇāmṛtāsvādanaṁ
- (sarvātmā-snapanaṁ) paraṁ vijayate śrī-kṛṣṇa-saṅkīrtanam
- (CC Antya 20.12)
So if you follow the instruction and if we chant, even though we do not understand in the beginning what is the effect of chanting Hare Kṛṣṇa mantra, but it will show its effect if you go on chanting. Just like I began this movement in America. I did not ask them anything; I simply invited them, "Please come and chant with me." And just see the result. It is practical. I never bribed them, nor I showed any magic. I simply asked them, "Chant Hare Kṛṣṇa." And see the result. It is practical.