Go up to descriptions and read about OP. It's super easy, any nut or seed oil will do.
Yes, Borax is what you need (20 Mule Team). I put a link to where I buy the Diatomaceous Earth in a post in this thread. The OP will stave off further gum recession, but I have yet to see it fully reverse gum disease and grow new tissue.
However, it was not until I started using DE that indeed I did start to see a change in my gums. I've decided to battle this from both sides.
I haven't started the Borax yet, but I have a trusted friend who says it's really good.