Is it possible to disable the copy-paste feature? I would prefer system-wide, but a solution for a single application would be a good start.
You might also disable the pboard process:
After quitting and reopening applications, pasting should stop working in most contexts. It also makes drag and drop and many services stop working.
You can undo the changes by replacing
Depending on what you are trying to do, you might use a background process that resets the clipboard periodically. For example save this plist as
Then load it with