Daoist internal alchemy, neidan, treats the hun as something a practitioner works on directly rather than as a fixed fact about the self to be merely understood. Because the hun are associated with wandering, particularly the dream-travel that Chinese thought attributes to their nighttime departure from the body, a hun that wanders too freely or too often was regarded as a sign of instability, and a settled, undispersed hun was correspondingly treated as both a marker of good health and a precondition for advanced spiritual practice.
Neidan techniques aimed at "refining" the hun, reducing their tendency to scatter and cultivating a more unified, stable inner state, sit alongside parallel techniques directed at the po, since the tradition's larger goal is typically described as harmonising or marrying the two soul-types rather than eliminating either. A hun-po imbalance, too much yang volatility or too much yin heaviness, was understood as a source of both physical illness and spiritual disorder, which is why hun-po theory sits at the intersection of what a modern reader might separately call medicine and religion, a distinction Chinese thought in this period did not draw as sharply.
The image of a wandering hun also fed directly into broader Chinese religious practice beyond formal Daoist alchemy: rituals to "call back" a wandering hun, performed for the seriously ill or recently deceased, treat the hun's departure as a real and potentially reversible event rather than as a figure of speech, one of the clearer points of contact between elite Daoist body-cosmology and the wider practice of Chinese popular religion.