Reading just the 1st message posted, there is so much to assume about all this, it's easy to pick a side based on local similar situations.....
If you are more in a housing area and not a farming area, you probably should be getting the manure out of there more often than every 6 years or so.
While I have a right to farm in my county ad make manure smells, I can't let manure pile up that long, would be a viloation of other rules.
Glad you are trying to consider the neighbors and despite the initial message, perhaps your neighbor is calmly addressing this as well....
Hope you find a happy middle ground.
A lot of the additives that are supposed to help with odors are for liquid manures, not sure you will find much relief from a bottle for your old piles of manure.
My wife picks up on smells that I do not - I wonder if there is some earthy odor coming from the old piles that some of us guys don't even notice, but bothers others????