As I described on the other thread, a dripper won't do much if anything to provide the correct level of air humidity your cham needs in your setup. Unless you raise the humidity level of the entire room (a bad idea for obvious reasons), he's going to get dehydrated. A free range can work, but you will need to find a way to mist it very thoroughly every day and keep track of the humidity carefully. It just won't work for him otherwise.
You can protect the walls and furniture by confining the mist to one area with shower curtains.