hello there,
how many orders are we talking about? if there handful 20-25 orders, then manual deletion is the way to go to keep the database & functional integrity.
however, if there are 100's of orders that you would want to delete, then it is time consuming and error prone.
Couple of my clients had the same issue where they accidentally thru CIM created hundreds of unwanted orders and the clean-up would have taken them ages to complete, not to mention their Sales Order Reporting went for a toss.
As a professional consulting firm, we do provide services to delete the unwanted sales orders thru a custom program which reads the order numbers from a file and deletes it - completely maintaining the data checks as well as the database/functional integrity of the system.
give me a shout, if you need further help,
-sanju