Brushing your teeth/mouth is too difficult
If you find this is true then there should be candy or something humans can chew on that cleans their teeth in the process. I refuse to believe toothpaste is the only way to clean ourselves in the modern world. Maybe like a gummy cough drop that dissolves into a foam like substance that you can swish around as you eat it and eventually it is just gone. Have various flavours like cherry, grape, orange, apple or w.e