I remember reading that nothing but incineration would work in the context of Food-and-Mouth disease, but it seems modern techniques in brain surgery do use bleach. Interesting.
Essentially, the only thing that works is disintegrating the prions. You can't wash them off, since you're simply washing them into the water cycle. You can't deal with them in a way that preserves other biological matter, since they are proteins, disintegrating them means disintegrating any other proteins in that area.