As a highly potent drug injected intravenously acts at once on the whole body, the transcendental topics of the Lord injected through the ear of the pure devotee of the Lord can act very efficiently. Aural realization of the transcendental messages implies total realization, just as fructification of one part of a tree implies fructification of all other parts. This realization for a moment in the association of pure devotees like Sukadeva Gosvami prepares one's complete life for eternity.
Only in the association of pure devotees are the transcendental glories of Lord Krishna properly discussed.
As far as the great devotees of the Lord are concerned, they can purify a degraded soul just by being them and what to speak of the benefits of their association.
Dhritarashtra was lucky enough to have a brother whose very association was a source of liberation for his frustrated life.
Stabilization of renunciation is possible only by association with bona fide saints and self-realized souls by which one can be engaged in the loving devotional service of the Lord.
By associating with pure devotees and by hearing them submissively, attachment for material enjoyment becomes slackened and attraction for hearing about the transcendental activities of the Lord becomes prominent.