Soaking your chain in motor oil, or any sort of oil for that matter, is a waste of time.
It only takes a few moments for a drop of motor oil to reach the friction points once you apply it. Soaking it won't do any more for the link than adding a drop of oil on it.
Motor oil is a very poor choice for lube. It must maintain a thickness of .001" to be effective and your chain will have used up/slung off the oil in no time flat. There are no tackifiers to help keep the oil adhered to the metals surfaces.
Motor oil does make a good mess and attracts dirt, but not near as bad as chain wax does.