Does Ibn al-Jawzi's mention of the story of Ja'far al-Khuldi's recovery from scabies by the blessing of the dust of al-Husayn's grave in his book "Al-Muntazam" mean his affirmation of the authenticity of this report?

This narration is greatly denounced. Historical books are not sources from which rulings are derived, and their authors often do not concern themselves with the authenticity of chains of transmission. Ibn al-Jawzi’s inclusion of it does not imply its authentication or justification.