By the time that West Poison Au Yeung Fung died at the summit of Mt. Hua in ROCH, he had not been in his right mind for at least seventeen or eighteen years. Just before dying, he regained at least a large part of his memory...he remembered his real name, and he remembered whom Hung 7 Gung was.
Nevertheless, Au Yeung Fung didn't strike me as being *cured* of his mental problems at the time of his death. If Au Yeung Fung were truly cured, not only would he remember everything and everyone, he'd also be looking to resume doing the things he had been doing before his breakdown in LOCH... i.e. attempting to obtain the *real* 9 Yum Jen Ging and managing his affairs as the Lord of Mt. White Camel. He wouldn't be hanging around with Yeung Gor.
Was there ever a way to cure Au Yeung Fung's condition, restoring to him not only all his memories, but his original, sane personality from mid-LOCH?