I thought that I read on BYC that the PDZ should not get sopping wet.I tossed down an entire bag of granular PDZ in my 8x12 run this spring and it helped with the stink from the wet sand. My run is covered but the ground was saturated from snowmelt. I also noticed that the areas where I didn't rake the PDZ in fully so there was a higher ratio of PDZ to sand dried quicker than spots that were mostly sand. I don't think PDZ packs down like sand so it dries quicker.
But your experience certainly contradicts that.
Come to think of it, I do have a couple of bags mixed with the sand in my run, and it seems fine with some moisture. I guess you'd want to be sure the run is covered, so it has a chance to actually dry out periodically during the year.