We had a couple of Digital Radios (Pure brand) that had a nice to the touch soft "rubber" (or rubber like) coating that after a couple of years, became very sticky.
I used Meths (Bunnings) and a cloth to clean all the coating off and succeeded in revealing the underneath shiny plastic case and both radios are now non-stick and work as normal.
It took a fair bit of elbow grease as the coating was quite thick.
Good luck.
Dennis