I often use Duplicate Cleaner Pro.
You can download a trial version from here. There are some limitations in the trial but it does last 14 days so it may be enough time to do a tidy up.
https://www.duplicatecleaner.com/
After install you just select the folders you want to scan, then it runs a scan and shows you the duplicates/triplicates etc.
You can then just select the ones you want to delete and it deletes them.
I think in the trial you are limited to 100 duplicates but you can just delete that 100 then run the scan over and over again till you have deleted all the duplicates.
As well as finding exact duplicates it can also find files that are similar to each other (99%, 98% etc) though these cans take a lot longer.