From my understanding your fermented feed should not smell like yeast or like alcohol. You are wanting to encourage lactic bacteria, like that found in yoghurt. It should smell sour, but never yeasty or of alcohol. I have read that you should use food grade plastic or glass to make it in as it will eat into metal (which will leech into the food).
I completely cover my dry feed in water so the water is higher by at least an inch. I keep mine inside and within 24 hours it's bubbling away happily. It may take a couple of days for your first culture to start (if kept warm enough) and after that just save a bit of the water to add to the next batch to seed it. I strain mine out through a fine sieve so that it's mush and not runny and wet.
I don't like to leave mine too long as it can become too sour, but I usually mix up enough for around three days. My quail love it, and have done from the moment I first offered it. I do it for my chickens as well. It massively reduces the smell of quail. I know this because my boys that live outside, and live on dry food, smell really bad compared to my indoor quail.
It is super simple to do and there are so many articles online about making it for pet birds and chickens.
I can't give any advice about amounts as I'm only feeding it to 9 quails and I kind of just tip a rough amount into my huge 'apothecary' jars that I found.
It is more work but they smell a lot less which to me is the biggest benefit.