i read that idee many times, but wenn i was testing the idea of using a condom i really can't figure out how to fit a filled condom in a sock. Or how to fill a condom in a sock without a tap. My sock ain't very stretchy either so you proberbly can't fit as much water in it. Condoms also like to gain back there original size, so they it will try to force all the water out, making you wet. So you have to keep the opening much higer than where the bulk of the water is.