When your toothbrush has done its duty, instead of kicking it to the curb, give the brush a second life as a helper around your house. After a quick spin in your dishwasher, that old toothbrush can be put to work doing a multitude of tasks, cutting down on the amount of elbow grease that goes into cleaning. Here are 10 smart reasons to keep your old toothbrush stashed with your cleaning supplies: