My experience with Brodak Crystal Clear has not been very good. Although others did not have this problem, I noticed that the gloss disappeared when raw fuel touched it. Wiping off the fuel also removed the gloss. I have no idea if it was softened as well. I did not try any other experiments with it after that.
I also had it turn an ugly brown in short order. When the dope arrived, I opened both cans to see if it was truly crystal clear. It was. Several months later, when I went to use it, it had turned an ugly brown. I disposed of it, not wanting to take any chances.
I have no idea if opening the cans then resealing allowed some contaminant to enter and cause the discoloration. No other dope I have had did that so I wonder about the formulation of the Brodak Crystal Clear.