Trick for vacuum-sealing food without a vacuum-sealer

Perhaps you've put food in a ziplok baggie. Perhaps you've tried to leave open just enough of a gap to push out almost enough air to consider it truly sealed. Perhaps, like me, you've even sucked out the last air through that gap, creating a genuine vacuum while filling your mouth with delicious, cold poultry slime. Here's how to do the same thing without risk of becoming a campylobacter campsite! All you need is a plastic tub or pot of water.