1 tsp Metamucil or similar soluble fiber
8 oz water
Mix 1 teaspoon of Metamucil with 1 cup (8 ounces) of water in a microwaveable bowl.
Place bowl in the microwave and nuke on high for 4-5 minutes (depends on microwave power) or until the goo is about to bubble out of the bowl. Turn off the microwave.
Let the mixture cool slightly, then repeat (microwave until about to overflow). The more times this step is repeated the more rubbery the substance will become.
After 5-6 microwave runs, (carefully - hot hot HOT) pour the flubber onto a plate or cookie sheet. A spoon can be used to spread it out.
Allow to cool. Flubber can be stored at room temperature in a sealed baggie for several months. It will last indefinitely in a sealed bag in the refrigerator.