Bear in mind, almost all oem leathers are clear coated with a layer of clear vinyl for protection, so ostensibly you are cleaning vinyl. To find out for sure;

You can test your seats by applying an alkaline cleaner such as Simple Green, in an inconspicuous spot (underside of front seat , between bottom and back rest etc) and if you get none of the seat's color coming off on a white towel, then you will know your leather is coated. If color does come off, you don't have coated. Most cars manufactured in the last ~15 years are coated, this has been my experience in my work anyway, and from the info I got from Ron Ketcham at www.autoint.com.

I have tried Lexol, and most of the other brands, and they're fine, but most of the time I use Murphy's Oil Soap and hot water with a clean white rag...

... But you can really use anything that safely cleans vinyl if your leather is coated.

Cheers.