You can use anything to put weight inside the hammock - Dog food bags.
I would be a little careful what I put in the hammock for weight. Dog food/cat food bags are big and lumpy. We buy in the 40 to 50 pound bags. The problem you should consider in my humble opinion is that the food leaves a little oil and SMELL of food, candy to critters.
I started to use a couple of 50 lb. bags of K9 food then thought about it for a minute. I do not want my dog to taste the hammock. My cat already chewed on the strap of my hennessy, I think the oil from my hands brought that attack on. Scents linger, you might not want something tasting you in the night. Anyway it is just a thought for your consideration.
You're absolutely right! Put anything like dog/cat food in a plastic yard bag before putting it in your hammocks! And wash your hands!
I got in a fight one time with a really big guy, and he said, "I'm going to mop the floor with your face." I said, "You'll be sorry." He said, "Oh, yeah? Why?" I said, "Well, you won't be able to get into the corners very well."