I came up with a bunch of them, some free, but I would hesitate to use any of them.

"Duplicate file removal software for OS X" was the Google string.

The danger with this type of software is that it is very easy to delete the wrong file if the application is set to "auto".
"Clean Sweep" was a program of this type. It was very dangerous but it did keep me in business for a number of years; replacing the destroyed OS on dozens of machines.

If you do decide to get one, be very careful about what you allow it to remove, do NOT trust it implicitly.

Good Luck

P