16:8 combined with removing certain triggers (mine are nightshades, yeast and alcohol) plus daily large doses of vit d and using coconut oil cleared mine. Cutting out sugar has helped massively with my psioratic arthritis too.
I think unfortunately what works is different for everyone though. But I was willing to try anything by that point and was glad I found something that helped.
I still do 16:8 but am much less strict. I can eat nightshades and yeast now too. Also happily I can drink wine. I still don't have sugar though.