... Or an automated way that could be run via MP on the command line is mentioned in this "Off Topic" thread...
http://nolanparty.com/mediaportal.so...pic.php?t=6569
This looks like it has alot of promise, but I haven't had a chance to try it out yet. From what I have read, it can even give you the option to output the tv show with no commercials, and ALSO a file with the commercials in it (just in case it cuts something it is not supposed to).