To build on bowtiesr4me's reply if it were me I'd remove the cables in question and soak them in PBBlaster or similar, keeping the knob itself out of the soak. As he noted the cable is a wire within coiled wire and definately not liquid proof. A good soaking with penetrating oil should get them as loose as they will get.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.