How to Delete Clock Entries on Closed Production Orders?

We have a few production orders that were closed out before the supervisor approved clock time entries.  I have accounted for the time/cost by doing a project transaction for each project affected however I’m now simply wanting to delete the time entries off the “Approve Clock Entries” screen.  Anyone have a trick to do this?

I thought I could simply delete them using the “Delete” button but that doesn’t seem to work.