Have you tried putting your toothbrush and toothpaste in the shower? I’ve struggled with brushing my whole life and this is the only thing I’ve ever tried that actually worked. I also put a brush and paste at every sink but the only time I can ever actually manage to brush is in the shower.
There are so few kids out trick or treating these days that it’s really not that expensive to do this now, too. I will never get tired of hearing excited kids say “THIS HOUSE HAS BIG BARS!!”