Make The Jello "Water": Pour the jello crystals into a bowl. Boil some water in the kettle. Add 3/4 cup of the boiling water to the jello crystals and stir until dissolved.
Add the rum and ice mixture. Stir until the water has thickened (which should take a minute or two). Remove any left over ice cubes.
Then refrigerate in the bowl for 15 or 20 minutes (The mixture should be gelled but not firmly set). Stir the jello to give it the appearance of running water.