I use it on bags made from grained calfskin, what Chanel calls caviar. This leather needs little maintenance, so if it's in good condition already I just use a tiny amount of the product (I think it's called leather moisturizer) on a soft cloth and gently buff it in. I think if it doesn't work it's more likely due to false application, especially too much product, than the product itself. So I'd say it definitely works for caviar leather really well, it even removed color transfer on a light colored bag.
But I'm not a Chanel leather expert, maybe additionally browse this care thread if you're not sure, I know many wrote there they use Coach products on their caviar bags:
Ok, all you wonderful Chanel experts: My first Chanel is a white caviar classic flap. What do I need to do to take care of it? What can I use to clean it? Should I treat it with something? I am terrified to change the white color at all!:push:
forum.purseblog.com
(but some people write there they clean their bags with a damp cloth, I would not do that)