If the remote computer is a TSM server or you have SANergy and maybe with
the SAN client you can delete the remote storage pool with the discard=yes
and it should get rid of everything.  I have not tried this in this
scenario.  Then redefine the storage pool and perform another copy.
However, you are vulnerable for the time it takes to redo the copy.

I am not sure why you are not just keeping two copy pools (one local and one
remote) in synchronization with the primary.

You would define a file device class on the remote system.