Once a week, you should pour about a half cup vinegar into your toilets and let it sit for 30 minutes. Next, sprinkle baking soda on a toilet bowl brush and scour any remaining stained areas. Afterward, flush. You can also mix the vinegar and baking soda, swish the bowl, and allow it to sit for 20 minutes before scrubbing clean. If you have stubborn hard-water or rust stains, you can do the same thing, but scrub the surfaces with a bit of steel wool. Of course, never flush steel wool down the toilet. Instead, rinse it thoroughly, set aside to.