You are not cleaning the wheels, you are stripping the chrome off of them layer by layer. What you are left with is the bare metal that is polished before the plating process begins. Chrome is not a type of metal, it is more like a paint, but it is applied in a electrostatic type process by dipping the base metal is different solutions to attract the desired finish.
When you are done, you will have a set of steel wheels that have no protection to them and will rust any time humidity hits them. Either you need to have them blasted and powder coated or re-chromed, or replaced.