Regular cream polishes are not recommended for shell. If you're talking about the cordovan-colored shell cordovan cream polish, that should be fine. But I don't think you're going to get the effect you want.
Are you trying to change the color of a pair of SHELL cordovan shoes? Or cordovan-colored calf? Because if they're shell, stripping them with renomat or another solvent is probably NOT a good idea. Shell doesn't really take pigment, and most people would say you shouldn't use regularly-formulated cream polishes on it. I don't think there's an advisable method for changing the color of shell, except for getting a pair in a different color.
I can see the benefit of something with at least a little bit of solvent in it to clean off the surface of the shoe (although obviously any liquid or cream being applied to a shoe is going to be a solvent for something). That said, what products are strictly moisturizers besides mink oil?