The PomaBrush is a simple, waterproof, all-silicone toothbrush that only needs to be charged three times a year. It would be a good option for people who go camping, travel for work a lot or just want a low-hassle electric toothbrush option. https://www.techadvisor.co.uk/news/appliances/pomabrush-electric-toothbrush-4-months-of-battery-life-3793316/