When my mother had chooks she used the water-soak method. She used a big plastic rubbish bin with a lid, put the manure and bedding in it, and covered it with water. As long as the solid stuff stays under the water, it almost doesn't matter about quantities. Once the bedding gets waterlogged it will stay under by itself, but until then use a stick to push it down occasionally like Ron said.
Mum would just keep adding more manure and more water as long as she could fit it in the container. Then she would scoop some out and dilute it when watering the garden. Fortunately Mum had a big garden because that bin sure did stink!
One time my Dad decided to rearrange stuff in the yard and tipped out the whole bin of disgusting stinky stuff. Mum was furious!
But all the solid bits rotted away really fast and for a long time after you could see exactly where it had landed and where all the high-nutrient liquid had run. Dad had to mow that patch way more than any other part of the lawn because the grass grew like nothing he had ever seen before and was a totally different shade of rich green. (Of course all visitors would comment on the one lush patch of grass and Mum took every chance to tell them how mad she still was with Dad for tipping out her precious manure!