After archiving or deleting items in Seller Central you can delete the MSKUs from REPRICE and LIST as well. To do this log-in to ScanPower at https://unity.scanpower.com.
Next go to the following link: https://unity.scanpower.com/inventory/cost
There you can upload a .csv or .xlsx file containing the archived/deleted MSKU information. The .csv or .xlsx should look like this with two columns: MSKU and DELETED: