Self-reference can be geometrically expressed as the Mobius Strip, alchemically expressed as the Ourobourous, linguistically expressed as Language Bypass Syndrome, medically expressed as Homeopathy, and musically expressed as the Shepard Tone. It is where beginning and ending, creation and destruction, up and down are confused so as to produce a sustained continuum. In everyday practice, it can be expressed as Similia Similibus Curantur: like cures like.
It is part of a preference in nature for Self-Generation, (DNA, universe, human invention, for example) – these things imply that the willing allowance for a things destruction automatically generates its continuation. The RNA and DNA molecule break down in order to replicate; the circumstances of the universes creation is echoed in every preceding things violent destruction; the more amiable condition is one that rolls with the punches, rather than putting up defences.
In Ideal Topology these states confer a successful bypassing of destruction by retentive allowance, forever breaking without frayed edges or visible joins. By extension, Poison/Cure self-reference is practiced by opposites either being one another, or being in inseparable proximity to one another.
In the case of the hair of the dog that bit you, a literal geometry of exchange is implied. A reversal takes place, allowing last nights poison to blunt this mornings hangover.
White wine can be applied to red wine stains for easier removal.
If the nettle leaf is rolled up so that the needles face inward it can be ingested without pain. The cure to the nettle sting is contained just behind each needle; whatever stinging sensation is felt in the mouth soon disappears as the acid is instantly broken down.