Oil Pulling doesn't cause gum recission. In fact my gums have made a small improvement in that regard over the last few years. BUT - it can look that way.

What OP does is reduce the inflammation in gums which makes existing rescission easier to see. I was shocked after I first started to see how recessed my gums were too. But after doing this for maybe 5 years now I can tell you OP doesn't cause anything but healthier gums.

The one supplement I know of that helps gums grow back (though there are others less well known) is COQ10. Some people even get the liquid form and rub it on the gums. Hmm, never thought of adding some drops to the oil every day. No idea how effective that would be.

Anyway, get the best quality you can (it can be expensive) and take high doses, but it works.