I'm sorry I mentioned toxicity in my original post. It was not my intention at all, merely to inform the original poster of the ongoing DAS purchase if he wants it. Next time I should be more careful on my choice of words. Most of us here deal with chemicals on a regular basis and understand the real and imaginary dangers. Let's drop this subject before someone else jumps in - there is no new information to discuss that we don't already know. Peace?
The Potassium alum also hardens the gelatin, but it is not an immediate effect. In fact it is used (or was used) in pickling to harden the cell walls to keep the fruit (and cucumbers) from being mushy. Why it is used in underarm deorderants, I do not know.
At least with LF landscape, a bad day of photography can be a good day of exercise.