It should be heavy enough to stay on the bottom of the sump assuming thats where it is and it will not make it to the oil pump thanks to the strainer, my only concern would be that where the oil flows from the sump into the filter/strainer it does not sit it in that small gap and restrict the oil flow to the pump if you could get it out i myself would want to, if you have exhausted all attempts and still cant find it yom may have no option but to take a chance. It may not work but can you get hold of a strong magnet and keep rubbing it along the bottom of the sump towards the drain hole and hope it drags it there i know its a long shot but were there's is a will there is a way.....