Usually when I destroy a page, I strive to keep some of the original work. Black gesso makes a nice surface, but the kind I have now is in a tube, and I find it hard to judge how much to add to the page. It dries fairly quickly, so if I don't plan ahead and have something to wipe it off I end up with solid black.
And that's okay. I prefer the subtle hints of color and fantastic textures you get by keeping some of the original, but black gesso makes a beautiful surface for using metallic, glaze and souffle gel ink pens. They're so beautiful, you can do almost anything and it looks good!