Split it up maybe into 1mil each, then paste them right into notepad then copy them from notepad into scrapebox.
By pasting them into notepad it turns it into te most basic txt automatically then copying it to SB should work.
Use gscraper, which dont have limit row in load lists
Try Textpad or excel.
Able to handle massive files??
cat bigfile.txt | sort | uniq > newfile.txt