Properly composted manure is non-toxic but then it becomes compost, not manure. As soon as you use the word manure, especially in its proper context, you are in trouble. I would not let you use manure if I was the pastor, either. It has to be composted first.
In your case you've already set yourself up for scrutiny by using the "M" word. It may be a lost cause. You might tell them you propose to use only fully composted "materials" for the grounds and see what they say.
Fully composted manure, or anything else, has three characteristics you can learn to recognize. Use your sight, touch, and smell. Excellent compost is all dark in color and you should not be able to recognize the ingredients due to the decomposition. If you recognize twigs that's better than recognizing banana peels. Twigs take a long time to decompose completely.
Excellent compost has gone through a heat cycle but it has cooled back down to room temperature. If the compost is still warm that indicates it is still in an early stage of the composting process. It needs to sit awhile.
And excellent compost smells incredibly fresh, like a forest floor after a spring rain. The smell is most important factor. If the compost smells rank, dank, yeasty, musty, sour, manuery, acrid, or anything else bad, then it is not finished composting yet. The entire pile should smell GREAT!
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