@rek thanks a lot for writing this up!
One thing that neither you nor replies have mentioned is using an electric toothbrush. Dentists here in the UK mention it on each visit and it did make a huge difference for me. You don't have to push so hard (so easier on the gums) and it still cleans better. The batteries are tiny so wouldn't add much load on the boat, but the ones that clean the best unfortunately have irreplaceable batteries so you end up having to replace them every 5 years or so...
@daaain Yea i tend not to mention things I'm not likely to use, but I could mention it for others, like i did with the water pick.