Removing Duplicates from Dial List
Export DialList is a subsection of Miscellaneous, which is a section under the Database Management link. Here is a screenshot below highlighting the subsection.
When you click on Remove Duplicates, you will get a popup message that says Warning: Please let the Remove Dupes process finish before leaving the page. If you leave the page early then your dupes will not be removed properly!
This is letting you know that leaving the page before the confirmation message will disrupt the process from finishing.
The Remove Duplicates process will remove all the duplicate phone numbers which will result in a clean, unique list.