Your plants will rise up and call you blessed if you give them that duck stuff.
Mine like duck poop soup (dissolved in cool water, not boiling water!), duck-enriched straw, duck-straw mulch, and the occasional straight poo treat. It speeds up my compost process, too.
If you do have an area where they can enrich the mud, that is wonderful potting soil, or an amendment to potting soil. I combine that with coir and put it in pots and wow, are my tomatoes happy!
I also noticed that where they can just be on soil, it pretty quickly disappears into the ground. We have a pretty well-drained loamy soil here. On clay, it could get pretty slick, I think.