I had not brushed with a commercial toothpowder product before, though had tried carrying baking soda on some backpacking trips for this application. I was never happy with the result. Mostly I think it was just that the lack of foaming and mint flavor, both of which I’ve been psychologically conditioned to associate with “clean”.
Eco-Dent was available locally, so I bought a bottle and started using it. Application is easy: wet the brush, squirt out a bit of the powder from the bottle’s flip top lid, and brush like normal. After brushing for a second the powder froths up, and the experience is more or less the same as brushing with toothpaste.
The label claims that the 2 oz bottle can provide “up to 200 brushings”, which I find to be inaccurate. My first bottle lasted me 350 days. I brush twice a day, so that is 700 brushings. That works out to be about $0.01 per use, which is better than any toothpaste can offer. (Perhaps they expect you to use more of the powder per brushing than I do, but I always use enough to generate the same frothy lather I’d expect from toothpaste.)
When travelling, I repackage the powder into a 0.25 oz bottle. That is plenty for a week or two, takes up no space in a toiletry kit, and weighs approximately nothing.
There are plenty of other toothpowders on the market, but I’ve bought another couple bottles of Eco-Dent. Between those, my collection of toothbrush heads, and a stash of floss, I’ll be out of the dental care market for a few years.