You don't need TinkerTool to search invisible files in OS X, actually.
Simply open Finder and then Command-F to open the Find dialogue (which is not the search function in the toolbar). Select the disk you want and then enter conditions as you wish (name date etc...). If you want to find an invisible file, select the Visibility option and choose 'Invisible' or 'Invisible and Visible'.
You can easily find /etc and httpd.conf this way.