The benefit of using this status is that orders will no longer appear in the default list of Workorders.
However, this status cannot be set in one click from the status dropdown.
It is applied automatically when a work order is completed from the checkout process.
Here are the steps to do it
Click on the "Checkout" button from the work order
Click "Complete"
Click "Payment" and click "Finish Sale" right away as the balance should be zero.
The work order now has the "Done & Paid" status applied