I do it for the goats and sometimes for the hens.
I have 6 plastic boxes with lids and a large kitchen sieve. Each day I fill one with a days worth of grain. I soak it in warm water for a few hours then rinse it and put in the box with the lid on and leave in a warm place (mine are in the utility room as it is next to the sink and the tumble dryer which is on so often it keeps the room warm

). Each day it gets rinsed in warm water. As one box gets used it is refilled and goes back to the bottom of the pile.
The grain needs to be whole as it won't work if it has been crushed at all. I use a mix of barley and oats.
Since I changed to feeding sprouted grains I never see undigested grain in the goats' poo. The hens go mad for it and wait underneath the goats' feeder waiting to steal any they can get.