Charcoal teeth whitening powder
If you are looking for a more natural solution, charcoal teeth whitening powder is good option, depending on personal preference. You also then had to deal with scrubbing your hand to get black powder remnants off and then wipe down the sink. This one was messy and had a lot of steps. You had to spoon (comes with the powder) some of it into your hand, wet your toothbrush and then dab the toothbrush in the powder.