If you change the match rules for your process, it is possible to re-match your transactions in order to test the changes you made. This will clear any actions that have occurred on the exceptions, including manual matches and manual interventions.
To re-match your transactions, go to General settings from the Settings menu.
In the bottom-right of the screen under the Danger zone, you will see a button to Re-match transactions.
As a precautionary measure, this action requires two-steps, with the need for the word REMATCH to be keyed in for the action to proceed.