Just for info, the wiki example will NOT show duplicates which exist on different named albums. Otherwise it should be fine. If you want to keep different quality versions ie flac at 44K AND 192 or 16 AND 24 bit recordings they will not show up using the code below. Don't think Bitrate will be very accurate as FLAC bitrates are listed as averages as they change all the time during the song, so these are not in the variables.
[Media Type]=[Audio] ~dup=[Artist],[Bit Depth],[Duration],[Name],[Sample Rate] ~sort=[Artist],[Name],[Track #],[Sample Rate]
Then you can use this and either add back [Album] or remove the [field filters] as you require.
you can import this using the import button on a new smartlist (or create a View to make it prettier/more usable for 10K albums) -- if the bit rate is not the same it won't show up as a dupe, same with the sample rate -- you can play also with removing the duration field as some duplicates come out to within 4 seconds of each other and will not show even though they are in fact duplicates
Might be faster to redo in iTunes, then reload the library not sure.