I’ve seen this mentioned a few times but I could never track down the original source. There were images all over social media explaining how to make a homemade ice pack but I wanted to give this homemade gel ice pack thing a try, especially since I am training to run a 10K in a few weeks. Turns out, it works perfectly!
EDIT: A word of caution about the alcohol. Don’t use scented alcohol because the odor will seep into the freezer (and refrigerator), even if you double bag it! Learn from my mistakes, people. You don’t want wintergreen scented soy milk. It just isn’t right.