Q: MacBok Pro Running Slow

Check the App store and the Internet.

Duplicate files are not the reason why your MBP is running slow unless they are taking ALL of your HDD space.

If you wish to pursue the matter any further, download and post an Etrecheck report:

http://www.etresoft.com/etrecheck

Ciao.

Another way to find duplicates...

See:  METHOD 2: Use Finder to Locate Duplicates

Here >  http://www.chriswrites.com/how-to-find-and-delete-duplicate-files-in-mac-os-x/#F inder

You're welcome

If you are referring to EtreCheck, it's safe and does not share any personal data.

Unless you're doing something very unusual, duplicate files are a non-issue. Searching for them would be a waste of time.

It's best to describe the functional problem, if you have one, in as much relevant detail as possible, rather than to say what you think is causing it or how you think it should be solved.