If you are working with a large number of duplicates (thousands) or if your machine is a bit underpowered, you may find the following method to be extremely helpful.
When searching for duplicates, you can cancel the process during the search. Using this method you are able to process smaller portions and complete them prior to moving onto the other duplicates. Simply initiate the search in DeDuper, after your results are filled to a degree (user choice), cancel the process. Your search will be left in tact, providing the ability to remove the partial results. Please note that you will need to use the ( X ) button and not the Pause (||) button in order to get the "DeDupe All" option.
Please be sure to relaunch TuneUp after removing tracks to ensure that TuneUp's cache is fully refreshed.