Interesting thread, as I'm looking also.
I,ve gone thru several pairs of the Sorel Caribou's and others, one pair of the Sorel's acted like the rubber rotted after a short time.
In the off seasons I started bagging these rubber types in a plastic garbage
sack, and has seemed to help in keeping more life in the rubber.
Kind of thinking static here might be part of the problem & as in, if they are left/stored on carpet its even seems to be worse.