Is the wheel Alcantara or suede?
Both can be cleaned and brought back to life, but with slightly different methods.
The company I used to work for used water, a toothbrush and microfiber towel with alcantara, and a Kiwi brand suede eraser and brush for suede. its is very easy to do and will make your old worn out wheel look new again!
MAcarbon's Blog | Keep Your Suede Steering Wheel Looking New
Beverly Hills Porsche Official Blog: What is Alcantara and How Do I Clean It?