My flour has soaked and I used it to make a simple gluten free loaf of bread. I used the Gluten Free Cheese Bread recipe minus the cheese. I did not add any liquid either. Here is the result. I pulled it from the oven, let it cool a bit and then sliced it and slathered with butter. My son begged for more and my daughter wolfed down a slice. I have to admit it was moist and fluffy. Very good and worth the effort.
To soak my flour I took equal parts of water and flour (ie 2 cups of water to 2 cups of flour) and added 1 1/2 tsp apple cider vinegar for every two cups. For one cup of brown rice I added 1 tsp. I don't think there is a right or wrong amount. It will just make it a bit more "tangy" if you add too much.
To your health!