Mix a solution of 2 parts linseed oil and 1 part white vinegar in a medium-sized bowl.
Absorb the mixture with a cleaning rag, and squeeze out the rag so you're working with a damp rag, not a dripping wet rag.
Wipe the cloth all over your genuine leather surface. Leave behind a light layer of film.
Come back the next morning and rub over the leather with a clean rag to remove that light layer of film you left behind the previous day.