Breaking form a bit, as this is not technically edible, I'm including this because although there is a notice on the package advising you not to swallow the contents, you'd almost certainly survive the resultant ordeal.
A recent emergency forced me to embark on an overseas trip and anyone familiar with the current state of the aviation industry and travel abroad in general will agree that this is a grueling task indeed. One of the most horrible elements of traveling is the filth your body seems to produce during the endless sitting and waiting. Grease and stenches that ought not be possible from pure sedentary activities.
The mouth is one of the most horrendously effected areas of the body. A vile film covers the insides and the teeth grow a thick pelt of fur. With travel restrictions as they are, you may find yourself without toiletries in such a situation or, not wanting to unpack the entirety of your carry-on luggage in an airport bathroom, they may be effectively inaccessible. But fear not, travelers (to the UK, at least) the Chewable Toothbrush is here to help you.
Depositing a one pound coin gives you two little, translucent-green balls containing an odd looking, plastic venus-fly trap. Directions simply instruct you to open the ball, pop the little plastic jaws in your mouth, chew repeatedly, and spit the contents out when done.
The tiny toothbrush is covered in a refreshing minty baking soda based powder. Funnily enough, it feels as though you're chewing on a little plastic toy you purchased from a gum ball machine. I walked around the airport chewing on this thing until I came dangerously close to drooling on myself and then did the sensible thing: spat it into a nearby garbage receptacle.
So, not really edible (unless you want to brave the sensations of those little jaws scraping through your innards and out the other end) but close enough... and effective too. If you're traveling and in serious need of an oral cleansing, I recommend it if they're available.