According to Osho, an obsession is a psychic wound—you cannot drop it by will. Instead, stop condemning or identifying with it; bring meditative, friendly attention to it. Simply witness it, with care and patience. Meditation is medicine: as you observe without prejudice, the knot loosens, its poison drains, and the energy transforms, naturally dissolving the obsession.
You don’t push an obsession away; you kindly watch it until it heals and fades.