The one thing you can't do (as far as I know) is ferment uncooked all raw grains unless amylaze is added artificially. You can add all the yeast you like but it won't convert of itself.
Sure you can, you just increase the risk of bacterial infection a bit. Take a wad of the soggy grain and chew on it. Or maybe just spit in the mash. There's amylase in your saliva.