How can I remove errant podcast entries in iTunes? I am using iTunes 10.6.3 on OS X 10.8

On my second generation AppleTV there are 8 podcasts showing that I have long since deleted. When I look in iTunes there is nothing there. I then created a smart playlist that would show only podcasts and it listed the 8 podcasts just as the AppleTV did. The problem is, in the smart playlist all 8 of the podcasts have exclamation points showing that iTunes does not know where the actual files are.

Seeing that I closed iTunes and edited the library xml file to remove each of the haunting podcasts. Upon opening iTunes the same entries show up again. It appears that the itl library file keeps adding them back to the xml file. Is there anyway I can remove these entries from the itl file directly? If not, how can I get these things not to show up on my AppleTV?
In iTunes, edit the bad podcast (Right click on it and select 'Get Info'). It will give an error and say it can't find the file and ask if you want to locate it. Say Yes and point the podcast to one in your recycle bin that is already deleted. Actually, any mp3 file will work. You could also make a copy of an existing one to use. Then you will be able to delete the podcast and send the file to the recycle bin. You can then use the same file for the next errant podcast. 

If you are deleting the podcasts from a (smart) playlist, then use Shift+Delete (on Windows) or Option+Delete (on OS X) to remove them from both the playlist and the library.