"You dont HAVE to brush your teeth..."
True. You just have to brush the ones you want to keep.
"Any inference that you will damage your teeth or health by not brushing for a week or two is totally absurd."
As a dentist, I find that statement absurd, MB. 2-3 days of not brushing will most certainly have an effect on oral health. I'm not trying to smack you down, but I don't want others to think they can get away with what you are suggesting.
Changing the topic, here's a photo of a man in Mali using what the Arabs call a miswak to clean his teeth. It's cut from a root of a very fibrous desert bush. They chew on the end for awhile to separate the fibers. It isn't a perfect brush, but it works sort of OK.