I have several sheets of negatives that are beginning to brown. Let's just say I thought I was too cool to properly fix and wash when I first got started. Luckily, I don't consider many of these shots to be any good anymore, but I would like to save a few. Is there any way to reverse or at least stop this damage? Short of scanning them in now (or printing them all) and discarding the negatives, what can I do?