Simple fly reduction

I ferment grains for my chickens. In the summer this means 3 half gallon mason jars that hold a days grains. Ideally I feed for 2 days, and fill the 2 empty jars, so there's always fermented grains. More than 3 days in our heat starts to get risky.
I add about 3 cups of grains in the jar and add about double the amount of water. The hose water comes out hot and stinky.  I try not to waist water, so when I fill the water, or grains first I spray down the roosting bars with the high pressure nozzle. The chickens don't seem to mind, but I just think it's gross to sleep in poop.
I started to notice when I am on task I can go about my business undisturbed. If I miss a few days I have to constantly swat flies. It was enough of a difference I noticed. I did a couple of very non scientific experiments where I didn't rinse the roosting bars for a few days, there was a lot more flies. I am convinced this makes a difference.
There's no getting rid of flies. Even though they are annoying disgusting creatures the world would be a very gross place without them. Also chickens poop everywhere all the time. I think because the only time chickens are still for any length of time is while they are sleeping. They even poop while they sleep from what I understand. So even though there's chicken poop everywhere, There's a larger concentration of it on and under the roosting bars. Removing most of the poop from the roosting bars, and now I spray off the poop stuck to the fence, and spray the larger piles of poop under the bars, seems to greatly reduce flies in the coop. This makes it so much nicer for me to do what needs to be done, and I imagine it is nicer for the chickens to not be constantly pestered by flies while they sleep.
I use the high pressure nozzle and quickly spray the bars down. Then I fill what needs to be filled.   Then I make one more quick pass over the bars fence and under the bars. This usually gets most of it, and makes a big difference. No chemicals, no sticky tape to get suck in my hair, no very stinky fly bag or trap. Just water that would be otherwise waisted.