I thought that might be the case. If I search for the tags I do not want, I have search for them individually. Otherwise it is hard to skip over the stories I do want. Now that I look back, I'm not sure what I was trying to do. If I can filter out the tags I do want to keep, I'll be able to remove the left over books. Than I can look at what is left of the tags I did not want.
I also tried to not show the tags I wanted to keep, but when I tried saying to not show tag B or tag C, they both show up.
Book 1: Tag B (doesn't have tag C)
Book 2: Tag C (doesn't have tag B)
While I had some luck using and to not show books with tags B/C, I got an error saying that the maximum recurrsion depth was reached when I tried to filter out the books with the tags I wanted to keep. How many things can you search for at once?
I guess I'll have to go through each tag I do not want manually to ensure that I keep the books I want.