I use barn lime it says it contains no caustic ingredients stir it in well and be sure to use it when the flock isn't inside . it's dusty.
I used lime to preven hoof rot in sheep and goats and it does have the ability to burn through soft hooves when wet, especially if it clumps as it left small craters in the bottom of their feet. I would be careful using it on wet duck feet based on that experience.
I have found chopped oak leaves do a great job of neutralizing odor around the swim pans. There is also Sweet PDZ that is supposed to reduce the formation of ammonia.
