Please choose the correct ending to complete the given sentence: Health: [header] How to bleach your teeth [title] Bleach your teeth with baking soda. [step] If this stuff can be found in toothpaste, it's got to work. Turns out there are free radicals in baking soda that can penetrate through your enamel, turning stains clear.

Ending1: To find an alternative, dump the baking soda into a cleaning bucket and mix it with sodium bicarbonate. Rinsing out with warm water will give your tooth enamel a solid surface to adhere to. Ending2: [substeps] Use a gel toothpaste to wax your teeth, including the membranes at the outer corners. This helps remove particles like bacteria that cause tartar and tooth decay. Ending3: Just dip your toothbrush in the stuff and scrub away for a couple of minutes, just like you're brushing your teeth. [substeps] There has been some uproar about just how safe this is, for the record. Ending4: You could also use peroxide in place of baking soda. [substeps] Although it's simply hydrogen peroxide, it still has some distressing properties, making it a great substitute for vinegar.

Answer format: ending1/ending2/ending3/ending4