Works, sorta. I went ahead and paid the $8 to not have to build a script from github due to needing API access. Even though it has been paid, it doesn't actually update the extension that I have. So the only workaround for me to delete more than one at a time is to repeatedly open and close private windows and relogin, and then it still only deletes 50 at a time. Makes me wonder if that would have just worked without paying for it...

Edit: Worked great after downloading chrome and using it there.