I did a search online to find out how to clean leather so that I wouldn’t have to get my jacket cleaned professionally. Let me just warn you, it’s worth getting it done professionally.
The advice I found was to mix 1 part vinegar with 2 parts linseed oil. Rub that mixture on the leather and let it sit over night before rubbing it off with a dry lint-free cloth. Well I never got around to the second part.
Think about it. Vinegar and oil? Sounds like a salad. Smells like a marinade. It was delicious.