I do leatherwork full time for a living, don't mean I KNOW more than anyone else though. All of those mentioned are good and will work to do some good,, bottom line is how old is the leather, how dry, how wet, and how it was tanned as what to use for best results,,
BUT in general to much of anything is not good or wore than nothing,
Mink oil is easy to find and use on boot leather in general, I like bear oil beeswax for if I had to use only one, and best all around is Montana pitch blend.. Just my opinion,, meats foot oil is great to treat dried out leather but will not help weather proof or keep nasty stuff out,,
There is difference with what you "treat" the leather with and what you "protect" leather with
Just like shampoo and conditioner and lotion for you hair and skin they all do a certain job
.
Montana pitch blend can do all those jobs for average use boot because the mink oil conditions the leather, and the pitch and bees wax seals and protects
Ken