Bag the contents and completely freeze them before sealing.
Put your vacuum sealer away and use an appropriately sized preserving jar filling it almost to the rim with product. Very gently tighten the lid using fingertips only so any gases under pressure can escape, but water can’t get in. Then entirely immerse and cook. Don’t be alarmed by escaping bubbles, a good sign. Otherwise you might experience a messy container failure.
Please share with us the advantage you gained by cooking in a marinade.