I am not an expert, and I did not stay at a holiday innnn ….
But I have heard thru the grapevine that Ballistol may help leather if you can stand the aroma.
However, I too have and use Skidmore and also that archival wax stuff whatever its called.
Skidmire first over numerous days until it is no longer absorbed.
Then that good museum wax stuff.
Hope this helps
I believe the Good Prof. is speaking about Renaissance Wax ...
It is a fine product! for wood & metal rust & tarnish protectant. and works on leather even paper.
I've used Skidmores many years for leather finish, just Skidmores or dyed and coated with Skidmores.
I used the same Skidmore for wood finishing.
Ballistol was developed by the Germans prior to WW1 for Gun cleaning, wood, metal & leather.
It also served the soldiers as a wound oil for minor injuries, lacerations and bruises.
Nothing will save leather from "red rot" as the fibers have broken down and have weaken beyond service,
However, Ballistol can soften and allow said leather for display purpose, (no field use) a while longer.