??? Really ??? Punch a hole in the top of a bottle of vinegar and sit the bottle in your toilet tank. In doing this you will save water, as the tank wont fill as much, the vinegar will clean your toilet AND tank on each flush, it leaves the bathroom smelling fresh and it doesn't harm any component of your toilet OR the environment when flushed. And won't hurt the dogs when they drink out of the toilet like the blue stuff does.
Spring-Cleaning That Won't Take Over Your Life: 8 Hours, Start to Finish