Here is a very good article about waders and other breathable outdoor gear...
Breathing Underwater | MidCurrent
Zach wrote this or a very similar article years ago in one of the big fly fishing magazines. In it he suggested rejuvinating your waders and eliminating 'wet-out' by using ReviveX (made by W.D. Gore) which I've had great success with since then.
I'm glad to see you reread the instructions about using Armorall. That just seemed like it would clog the pores on breathable materials.