I believe the intent is to keep it moist and with available oxygen intil it sprouts, to develop the enzymes necessary to convert the starches to sugar in the mash. Think of it this way: you are trying to recreate the conditions of a seed kernel in the soil. It has both available moisture and oxygen. I believe if you soak it without oxygen for 5 days you will not get the desired results. Perhaps if you spread it out on a towel, moisten and cover, similar to what RM-NM described for his seed proofing.