Hi,
You can check it this way, As you mentioned you have removed everyone group from permission but you are still getting files in Alfresco. Say if you are searching by users "testUser", <strong>login to Alfresco with this user and check are you able to access Data Dictionary from Explorer / Document Library ? </strong> If yes, that means user still has permission on it and that is the reason you are getting it in search result. So you need to make sure that permission are removed correctly.
If this is your custom search, and you have implemented a custom search api, then better you exclude that path from query, so there won't be any need of adding / removing permission for any user/group in Alfresco. It's just that it will not search in that folder or its children folders.
Regards.