For a true patina it is all about time. The more use the leather gets, the more it will luster.
If you are looking for a quick result I would try using a neutral shoe or boot creme. Treat it as if you are polishing your shoes, clean the dirt off, apply a tiny amount, allow to dry and buff off.
I think Saphir Rejuvenator is a wonderful product. But remember the less your use the better the results.
Good luck, and post some images when they are done.