Sandpaper! Honey, that is a terrible idea. As you found out, all that will do is abrade your skin and possibly leave grit embedded in your epidermis or dermis, inviting infection and permanent skin damage.
There are only two options for facial hair removal: laser or electrolysis. May I ask why you are so averse to trying laser? From what you say, the prospect of keeping your facial hair is worse.
With kindness,
Terri
Edit: In response to the bleaching of beard shadow, again there is only one real solution: removal of the melanin-producing cells. Bleaching would seem to be a poor solution. It has to penetrate the skin, or get well into the follicles.