Would you eat this chicken?

Fortunately, between the freezing, thawing, washing and cooking, he probably does wipe out most of the bacteria and gerbies. Believe it or not, the human immune system is pretty good at what it does, and fortunately most of the time even in the most appalling conditions it still protects us. Salmonella can't survive cooking, which is what is saving him. Where salmonella is a risk involves foods that are eaten raw, or cross contamination from the uncooked chicken. Even under the best conditions, chicken carries salmonella, and we don't have to worry because we handle it correctly in the kitchen and we don't eat it until it's fully cooked. So while it is all rather unappetizing, the real risk is mostly making sure he's good and careful with the raw chicken and clean in the prep area. You would probably never get him to agree to purchase the bird elsewhere, but maybe you can convert him to smaller storage bags for the freezer. The rest, perhaps you just have to look away from and figure at 76, he's entitled. Once it's cooked, it's safe enough to eat- though I'll leave that decision in your hands. It won't hurt you, and it will keep peace if you do. Or you can handle the marketing and storage, as a loving daughter in law, and take care of it yourself.