I also live in the PNW and have tried straw, sand, pea gravel, and wood shavings. A lot depends on the run/coop you have. My run is on bare ground and covered with a tin roof, and it has a tiny pond insert. My attached "coop" where they sleep has a plywood floor and is enclosed with a couple small windows. My original intention was to try the deep litter method because I read so many positive things about it prior to getting my ducks (I have 5 right now, started with 6). So I started with straw inside and straw outside, with pea gravel going around the pond. It was hard to keep the straw dry, and I was concerned about aspergillosis due to mold in the straw, plus the ammonia smell building in their sleeping area - which is 4x12. I started trying to remove wet and poopy straw and replace with dry straw. Meanwhile, I had a duck with a skin issue (which turned out to be feather-pulling) and my vet suggested she might be allergic to the bedding, so we switched out to wood shavings. I found the shavings way easier to keep clean because you easily scoop out the poopy and wet areas without long pieces of straw clinging every which way. A couple months later I had a couple of ducks get bumblefoot at the same time and I started to get worried it was from the pea gravel, so I switched to sand around their pond. For me that was a mess. It was winter and the sand did not drain at all. So hosing poops off was a mess because I would get standing water. My other option was shoveling off the poop and replacing with fresh sand, which was cumbersome. It also smelled so bad! I got rid of it early last summer and threw it in my yard and it still kind of stinks when I walk by that area. I know it works well for some people but not for my setup. I went back to pea gravel that is very deep and now I hose it down everyday and though it stays wet in the winter, it's still pretty clean. Except for where they have drug wood shavings into it. Like an above poster, I try to every few months shovel it into a wheel barrow and clean it. It's laborious, but works pretty well. I've only had one case of bumblefoot since I took the sand out, and I don't think that was caused by the pea gravel, which I don't have much of, since that duck doesn't spend much time over there. So for now I am sticking with the combination of shavings and pea gravel, though I haul out a lot of shavings to my compost pile every week. Every morning I scoop out the wet and poopy areas and replace with a fresh sprinkle of clean shavings and I don't have any odor issues. Hope you come up with something that works well for you. Everyone's situation is so individual, and ducks are just messy no matter what.