Recommended to me over 30 years ago by a third generation Italian cobbler who took care of the local police department's leather goods. He said; "Rub it in with your hands. Good for your skin."
Lexol...reportedly used successfully to keep/restore War Between the States era tack (reins and bridles). Leather dries out. Lexol restores the oils leached out by aging and/or being soaked with water from time to time.