Training in the U.K.A. (An English organisation)we recognise Rokkyo as a valid technique. Tim Heffner's description including the ude hishige part is accurate. Certainly elbow or arm crushing is an apt translation. The technique is extemely good defence for a tsuki thrust with tanto, jo or bokken. With care you can use against bokken shomenuchi or during bokken partner practice as tachi dori. Tori should try and lower their centre so that the hand that takes uke's wrist does so from almost underneath (keep your elbow down)- more difficult with weapons - so that the action of rotating uke's arm has the full effect of taking their posture. I have always found this excellent for strong people who do not expect to be moved in this manner. And yes it hurts !!
Tim - I'm not sure about your described seventh technique - this sounds more like one of the variations of shihonage for a different situation.