So I got the hydroxyapatite. I have been emptying a capsule in mouth and letting it sit for awhile. Has anyone used it as a calcium supplement? The reviews on Amazon talk about it being great for bone health.Funny you mention this. I was looking at that very supplement, thinking of doing just that. I'm not certain what the consistency of magnesium stearate is like, but that could be a factor in how well this powder is brushable. I've opened other capsules for mixing, that had rice flour, and the rice flour did not mix well at all. I'm guessing magnesium stearate may be more dissoluble. I may try this, and if it's not good for brushing I'll just add it to my mouth wash.