The safest of all non-professional means can rightfully be considered activated carbon. It does not lead to negative consequences in the form of gum disease or thinning of tooth enamel, it has no taste or smell.
The only thing, if you decide to whiten your teeth with charcoal, do it in the evening because after the procedure the teeth and gums can stain black for a short time.
As for the methods of using charcoal – you can grind it, add it to toothpaste and brush your teeth with this mixture once a week for a month. For a tooth whitening course, it is recommended to have a separate toothbrush with soft bristles so as not to damage the enamel.
You can simply crumble 2-3 tablets of coal, add a little water and brush your teeth with such “pulp”, then repeat the procedure with regular toothpaste.