A better way? to keep RTV usable.

I also use a screw and usually put plastic over that and rubber band it. I've never put it in the fridge but I do put my CA glues in there and they will last a couple years without stiffening up whereas on the shelf they only last 3 or 4 months. Might work for RTV but I've pretty much pushed the limits with my wife and her condiment shelves.