Best water ballooons...Im looking to be creative with some water balloons! any creative suggestions?!?

IM GOING TO HAVE A MAJOR WATER BALLOON WAR AND I WANT TO FILL MY BALLOOONS WITH CREATIVE "JUICE" SO TO SPEAK! IT CANT BE ANYTHING THAT STAINS CLOTHING OR WILL STING YOUR EYES ECT... PLUS I NEED TO FIND A WAY TO FILL THE BALLON EFFECTIVLY AND QUICKLY... ALSO I WOULD LIKE TO MAKE A HANDHELD SLING AS WELL! ANYONE HAVE ANY CREATIVE IDEAS?!