Finally figured one out that works for me, not too salty or abrasive.

10ml (2tsp) Diatomaceous Earth (food grade). ~ rich in silica, gentle polisher.
5ml (1tsp) Bentonite Clay ~ gentle polisher, mineral rich, detoxifying.
10ml (2tsp) Cal/Mag powder 2:1 ratio (this is sold as a drink mix). ~ re-mineralizing.
10ml (2tsp) Baking Soda (aluminum free). ~ gentle polisher, bacteria eliminator.
10ml (2tsp) Organic Orange Peel Powder. ~ natural whitening agent.
5ml (1tsp) Sea Salt (I used high mineral pink salt). ~ gentle polisher, natural anti-bacterial.
50ml (3Tbsp+1tsp) GMO-free Xylitol (I powdered this in a spice mill first) ~ anti-bacterial, decay prevention, plaque reducer.
*optional - 10 drops liquid trace minerals (sprinkle in and mix, if you wish you can run everything in a spice mill to make sure the liquid combines evenly with the powder). ~ re-mineralizing.
Combine all ingredients well and store in an air tight container. Use just a pinch on a wet or dry toothbrush. This makes 100ml of dry powder which could easily last for a year depending upon volume and frequency of use.
If you would like to flavour your tooth powder you may add a maximum of 20 drops essential oil of your preference. I used a combination of fennel, wintergreen, and cinnamon which is quite nice.
If you prefer a paste to a powder melt 45ml (2Tbsp) coconut oil and vigorously stir in the dry ingredients. Spoon into an airtight container and scoop out small amounts as needed. If the resulting paste is too thick or hard you can add additional coconut oil.
Even my children like this recipe, there's enough sweetness from the xylitol to offset the saltiness of the other ingredients. There are enough other powders to dilute the abrasiveness of the baking soda as well so there is no risk of damage to enamel from daily use. Oh, and the vitamin C in the orange peel powder seems to react with the baking soda to create a mild fizzing action that's fun! I'm thinking of using lemon peel in future batches for a more tart flavour to enhance the sweetness, should be an interesting experiment.
The cost of purchasing all these ingredients was quite a bit so I recommend making this with friends who all want some and are willing to share the investment dollars. I've made up several jars to sell next time I've got a table at the market (along with deodorant I also make) so that's an option for you as well. Just take care to keep things as clean and sterile as possible and make sure to provide a list of ingredients with jars you give away or sell.
Cheers!

~If it uplifts and inspires you, do it.~