It couldn't hurt but I don't think you will see any real advantage from it. Keep the unbalanced cables as short as possible. Cell phone interference was more of a problem in the past than it is now and the main point of leakage is going to be the connectors, not the cable, as long as it is shielded.
I might be mixing up terminology here, but I do not think there is such a thing as an unbalanced cable that is shielded. Without looking it up, I think unbalanced cables use the shielding for ground, or something along that line.
Along those same lines, wrapping a random amount of ferrite around a cable seems about as useful as putting a random resistor, of capacitor, in a circuit. It may, or may not work.
I am not an EE so I could not be right.