The celebrated Arcanum Tincture for the stone and gravel.
The pattern
This still is filed under Borrowed medical authority.
Define
The claim wears a lab coat: a diagram, a percentage, a clinical tone that is not necessarily a clinician.
Mechanism
Authority costume. Science-looking form transfers trust. Use it only when the substance matches, or we are documenting a historical mechanism. We do not recommend the abuse.
Verdict
We have real evidence and the buyer needs it in a form they already trust: a chart, a protocol, a named standard.
Why it works
It uses a 'damaging admission': admitting the medicine causes pain: to dramatically increase its credibility. By contrasting this temporary pain with the 'dreadful alternative of the knife' (which was often fatal in 1799), the choice becomes a no-brainer.
Steal this when
Selling a difficult or unpleasant solution where you can build massive trust by admitting the downside, then contrasting it favorably with a far worse alternative.