Hold the book closed tightly and use a soft brush to clear any loose soil from the page edges.
Use an artist's gum eraser to gently remove as much of the spot as possible while you hold the book closed. Be careful not to damage the pages.
Dip a cotton swab in household bleach and dab it onto the spots. Don't use a heavy hand--the bleach will weaken the paper.
Gently rub the fore edge with very fine sandpaper if the bleach treatment doesn't work. You may be able to sand off the stain. Don't do this with a valuable book.
Open the book and check for stains on the pages. Use the cotton swab dipped in bleach to treat them. Dry each page thoroughly before you continue to the next.
Remove excrement from glossy dust jackets with a soft cloth dampened with lighter fluid. Rub the stain until you've removed as much of it as possible. Don't treat dust jackets with bleach.
Clean leather bindings with a soft cloth dampened with lighter fluid then use a leather conditioner formulated for books.
Use the gum eraser on the bindings of hardcover books with paper-covered boards. Don't treat these bindings with bleach or lighter fluid.