There is not a lot you can do as chins are constant chewers and will chew practically everything
Mine come out for their 'free runs' in my hallway. They get the hall, the stairs and the landing to play on and the only damage that they can do is nibble the skirting boards. I do try to cover the skirting boards up with sheets etc, but they seem to dive underneath and still chew
We have even gone to the desperate measures of stripping all the wallpaper off the walls in the hall, stairs and landing as the little devils were chewing the paper too

So now .... the walls are just plain bare and painted