The wiki entry will work, but I think it depends a lot on file size, which can vary for a couple of reasons (eg. flac compression settings, different ripper codecs etc.
If you have a large collection, this might help you too
[Media Type]=[Audio] ~dup=[Name],[Album],[Duration] ~sort=[Filename],[Album Artist],[Album],[Track #],[Name],[Disc #],[Artist],[Bitrate]
this works off of duration, and I added in album too. In other words if you have a Best of and an original album the song will not come up as a duplicate. Remove [Album] and you can run a search just on the song name.
I use this in a view like this
You can copy code (or strings from the wiki) and click the import button after clicking set rules for file display, in case you didn't know already
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