Yeah -- disparate tag soup is a mess at the best of times. 10 books worth, all in one, must be even more fun.
Worth noting -- Diap's plugin can match and remove the attributes of a tag, instead of the tag itself. Also, ISTR you could sneak around the back and modify the config file to add extra target tags.
...
Usually I go through the styles, figure out which ones are junk, delete them
from the CSS, and then use the Remove unused class attributes to clean up afterward. It just seemed faster to me than doing it the other way around (attributes then styles).