Just an update. Mazuri Waterfowl Starter was fantastic the first week and is a great feed for many reasons. The 25 pound bag goes quick when you have 12 little ones devouring it night and day. As the bag of feed is getting lighter and we are now on day 20, I've transitioned to 1 part Mazuri, 2 parts Purina Duck pellets, and 1 part dry oatmeal. Also adding lots of grass, clover, and dandelions plus outdoor yard time, weather permitting.
As far as lessening odor, I don't think Mazuri made much of a difference. Goslings and ducklings stink. The little pellets do float. The Mazuri does retain its shape with water and the birds never had a problem with clumping whereas duck chow turns into a wet thick paste.
The use of a 5 foot diameter wide plastic pool is a vast improvement over anything made of cardboard. Pine shavings definitely is the way to go for bedding after the first week using shelf liner. The makeshift gallon jug water containers are key.
I appreciate all the suggestions on this site and the many years of posts. Made the process much better! Looking forward to the day when my dirty dozen is fully feathered and outside!