Huberd's Shoe Grease, good stuff.My favourite old safety boots lay neglected for a couple of years. What's best to dress and waterproof the leather.
Your quote "Not sure what's going to rot the stitching..."I looked up what's in Dubbin....
Dubbin is traditionally made from a mix of waxes, fats, and oils, such as beeswax or tallow, and neatsfoot oil or lard, to condition and waterproof leather. Modern commercial versions may also include petroleum jelly, paraffin wax, and other natural or synthetic ingredients like glycerine, resins, and vegetable or mineral oils, with some variations being entirely plant-based.
Used to use dubbin but it leaves a sticky finish that never dries fully. It attracts dirt and you cannot keep the boots clean.
I have switched to leder gris, a mixture of natural oils and beesax. It feeds and softens the leather and leaves a waterproof dirt repellant satin finish
There is a version with more beeswax if you want a shiny finish.
https://www.altberg.co.uk/boots/leder-gris-bootcare-wax
I would agree with that about Dubbin.
I use Beeswax stuff now on the Blundstone boots I always buy for work.
But this comes from the man who has - in the past scraped all the dried up bits from loads of old tins of multicoloured brown/black/neutral shoe polish tins and melted them on gas ring - given it a stir - and used it up on my work boots.