I was cleaning the mouse poop out of my darkroom and found an old bottle of GAF Flemish Toner. I bought it lots of years ago and it was probably old then. Doesn't look bad, i.e. it hasn't turned a funky color, but something in it has solidified. There are crystals in the bottle. Does anyone know what this is and how to bring it back to life, or is it destined for the toxic waste dump?