Another saddle-height rule-of-thumb, and the one I always go by, is to put your heels (in your cycling shoes) on the pedals and pedal backward. You should just be able to do that without rocking your hips from side to side. If your hips move, it's too high. If your knees and/or feet still splay out to the side after doing that, raising the saddle further isn't going to help, at least not without adding other problems. And that could just be the way your body is built.