Mix 1 part rubbing alcohol with 3 parts water in a ziploc bag and put in the freezer.
(The alcohol will prevent the water from freezing completely.)
When it’s frozen, wrap with a towel or cloth of some sort and apply.
If the mixture freezes, just add a little more alcohol. If it’s too slushy, add a little more water.
Check out what onegoodthing’s Jillee does with this! You’ll love it – think custom cover and colored ice!