OK then it is not suitable. The ways for getting rid of these through standard process is only by deleting them from the system. And for deleting them the precondition is that they should not be in use in any of the PM objects. I am yet to learn about any alternatives methods are there in standard without deleting. If it is a must, probably ABAPer should be able to help by creating a custom search help and assigning to the Data element.
There were discussions in the past. I did not remember the outcome. You can search for them. If find I'll update this post under PS
Good luck
KJogeswaraRao