About This Answer
Asked when he began seeing the unattractiveness of the body and realised impermanence, Ajahn Dtun says a vivid asubha nimitta (image of unattractiveness) before ordaining turned him from family life. Within about four or five months as a monk he let go of the coarse portion of identification with the body, seeing people and himself in stages of decay, and saw the Dhamma as Venerable Kondañña did: whatever arises, ceases.
The moderate portion fell away in his second year, and before four years were complete the mind repeatedly entered emptiness until all attachment to the body was put down, ending greed, aversion and sensual desire. In those years people looked like skeletons or decomposing bodies, and the body could appear as a mass of earth or a stream of water; he notes the forms of asubha are far more than ten. Now he simply sees people as people.
He describes removing defilements every time they arose and never eating with greed, and leaves listeners free to believe it or not.