By design, TuneUp will read all audio files of a compatible type. Unfortunately, if your spoken word, podcasts, videos, movies, voice memos or audio book tracks are MP3 files or MP4 files, there is no way for TuneUp to effectively distinguish these tracks from the music files that are fully supported. This poses an issue, as you may have experienced.
There is however, a systematic way that you can work with your music library and TuneUp.
Using the "Dirty Playlist" method you can also sort your results by a variety of parameters. The preferred way for supported music content is by artist. However for this purpose, Author's name seems to be easily identifiable when looking to weed out audio book material for example. For Voice Memos, you can sort by artist, genre or Album as shown in pic.
Another method would be to "Tag" all Non-Music tracks so that way if they appear in your TuneUp "Dirty Playlist", you can easily sort by your comment and remove them from the playlist.
To do this: Make a selection of all of the unsupported material that you identified and update their comments field. Once you have updated your comments filed with "Audio Book" or "Podcast" for example, you can then sort your playlist by comment, removing the unsupported material from the "Dirty Playlist". You are now free to process all the leftover files by artist feeding them into Clean. This method not only speeds up the cleaning process, but it is also the most efficient.