The only way to remove all is to do the radio reset, but if you have any other working devices those will all have to be paired and setup again.
Other option is with a USB stick which is detailed in this community guide: Z-Wave Ghost Removal using a UZB-Stick - How To
Also if the refresh refuses to give the remove button it is possible the device you tried to pair is still pending and on. Could try pressing Discover to see if by chance it finishes pairing it.
