Hi all, I started using a 33% magnesium chloride mixture. I use less than half a teaspoon, it's strong stuff. Works better than anything I've tried for sensitive, bleeding gums (essential oils, salt water, mega dosing vit.C) . I use it after stoking my teeth (also highly beneficial) and keep it in my mouth till my gums no longer feel sensitive (it will get worse before it gets better), this can take anywhere from 1 minute to 15 minutes.
However! I measured pH and it's too low for around your teeth (5.75, should be around 7), it can wear away enamel and make you prone to cavities. My teeth are very sensitive to cold now.
Because it works so well for gums though, I wanted to change the pH with baking soda, but it started to fizz and was not effective anymore.
I tried magnesium sulfate, but it didn't work and the pH was too low also. I'm not even sure how it works now: antibacterial action, magnesium absorption? (Could still be, in my experience magnesium sulfate barely gets absorbed.)
If anyone with a chemistry background now what could work to change the pH, I'd love to hear! And I hope my info was helpful.