Got it. Personally, without knowing the full details of what you're planning, I would not recommend doing it with a processing report.
Are you planning to only zero out the value entries for the item charges, or zero out and then change it to the correct amounts? If only zero out, won't the inventory subledger item cost of goods sold not reconcile to the cost of goods sold posted by the system in the GL? In the GL you have the original cost which includes the item charge, in the inventory subledger you will have the item cost excluding the item charge.
Also, if the original item charges were applied to shipments, that means the shipment entry is fully closed in the item ledger entries if Adjust Cost Item Entries has been run, or its scheduled to run automatically, and the item card has cost is adjusted=true. Technically, if you modify the value entries now, the system should not do anything further. But then if you do this, your inventory subledger or purchase/sales subledger (depending on where those item charges came from), will not reconcile. This is a big issue to me. It would make having an audit trail difficult and incorrect. For example, your auditor picks a random invoice to look at. The item charges on that invoice that are posted to the GL are correct, but if they look at the inventory subledger, the item charges are not there as they've been zeroed out?
Lastly, can I confirm the purpose of doing this? If the accounting entries are accurate, that means the GL is accurate? So really, the only problem is with the inventory subledger having the cost distribution among sold items incorrect. Do you do reporting off of the inventory subledger, and this is why this correction needs to happen?