Greets,
I used to think you had to hang em for a few days, but then three years ago it was way too warm to hang em more than a day, and I had a nice doe that I couldnt afford to take to the butcher. So after consulting a freind and a butcher, I boned her out, and soaked themeat overnite in cold water. I add salt to my water to take the gamy taste out, but you dont need it. As for my deer, best venison I have ever had, including ones taken strait from the feild to the butcher.
We do always gut them in the feild where they fall, or neerly there, and skin them as soon as we get em home.

Just my uneducated opinion!
Terry