I also tried the potting soil with the gel polymer crystals years ago. They stay too wet here, drawing on all the humidity in the air. Never really dry out. Might be ok in the winter, or for some really water-loving plants, but whatever it was that I had potted in that stuff died amazingly quickly, and it was obviously root rot from staying too wet, as I recall.
Rick, with your clay soil and living in the PNW where it rains a lot, I'd be worried that the crystals might not dry out, and could possibly make matters worse. Recommend you try a small, controlled experiment - maybe in a tub or big pot? - before you go for 10lb. of crystals. They're not cheap and might be impossible to remove once you mix them into an area of soil.
Compost has the same properties, in a cheaper, more natural and I think more effective form. Cellulose fibers swell up like tiny sponges when they get wet, and shrink to leave air spaces when they dry.
