Lol!
The only thing I can think of is people who detox, or who do this "health fasting" for weeks and months when they don't eat anything and only drink water - after a while their tongue becomes covered in white slime which stinks. Health professionals believe it is one of the evidence that the person is finally getting rid of all "bad things" in their body, which accumulated over the years of wrong diet.
And so, because this slime thing stinks, what such people usually do is brush their tongues every morning with a toothbrush. So perhaps you can develop produce and market through your website a special brush for such purposes??? You could similarly design it in different strengths, i.e. mild, strong and soft. You know, for hygienic purposes, after all you don't use your hair brush to brush your teeth, why should you use your tooth brush to brush your tongue??