I used Citric acid this year on my elk. Im not impressed and I will not use it again.
In my experience it did very little to keep the flies and wasps away. They would leave when I first sprayed, but would return in a few minutes.
The citric acid damaged the meat. I believe this happened because I was increasing concentrations in response to the flies not being detered. This is the same mechanism that is used to prepare ceviche, where the citric acid in limes is used to cook meat.
I increased concentrations with each application until I was using a fully saturated solution of citric acid. Still, the flies and wasps swarmed and landed.
It took me 5 days to get my meat out. Temps were getting down to about 42 F at night. The meat was hanging on a shady north slope for 1.5 days while I ferried it down to a river, from the kill site at 11,500' to the stream at 10,200'. At the stream I submerged the meat in trash bags in the creek during the day and hung it out at night. The stream was the single most important factor.
Most of the research found in literature regarding citric acid use for fresh meat preservation is performed in an tightly controlled environment. Wild game meat care in the backcountry is far from controlled and as a result of my experience this season, I personally find it futile to try and take this approach. I feel the time would be better used transporting the meat to a consistently cold environment, such as a stream, lake, or cooler full of ice.
I certainly appreciate the fact that using citric acid spray can't hurt the process and that everything should be done to prevent spoilage and contamination.
But there is apathy in thinking that the use of citric acid, or any other organic acid, will be some sort of game changer. Getting the meat cooled down and maintaining cool temps is by far the most important task at hand once an animal is down. There are many ways to accomplish this in the mountains and using a chemical agent is, in my opinion, not a substitute.
For those that have had success with this application, more power to you. But I did not find success and I will not waste my time with it in the future.