Homemade ice packs from dollar store sponges soaked in water and put in ziplock bag. Sponge absorbs water when thawed ----- I wonder how a sponge would work for a homemade gel icepack for injuries. The gel in my store bought gel ice pack squished flat unevenly when I used it for a recent knock on the head. ----- A small gel ice pack: 1cup dish soap and 1/3 cup rubbing alcohol frozen in a zip lock freezer bag. The more alcohol, the softer the frozen gel pack.