Normally you'd fire up a separate environment, mock the process and see if it produces the expected results. By the time you put 'test entries in a production bucket' there are so many lines crossed that it likely won't end well even if the tests do pass.

We tend to only test what is being tested. So, most DB calls are mocked in our unit tests. For stored procs or other tests that need to be run on a DB, we use a test DB that is setup to mirror production.

I'd bet there are a 100 different answers to your question though. This is the way we handle it.