Hey possumqueen, I grew up in Issaquah, and I thought THAT was rainy, but I think Olympia is worse! Issy sure has changed...
I don't worry about composting per se. I just throw everything together and let it rot (I guess you could call it cold composting). The stall dri definitely helps dry the poo out, which I guess would help with the smell. My chicken's poo just doesn't smell that much--I have never noticed an odor from the poo bucket. Maybe because they get lots of greens to eat? (chlorophyll helps with smells). I just wouldn't worry too much about the smell unless you have an issue, especially with just a few chickens.