It is difficult to know what Wang xiangzhai did really teach for the following reason : Most of his disciples did receive an education with Yao zongxun or had already a long experience of different schools of the chinese martial art.
It seems that the simplest way to perceive Wang xiangzhai's yiquan is by trying to understand the numerous comments and writtings he left to us.
In his interview by the people's daily, the master did express himself in those words, rough for the wushu community, that reveilled us the differents researches he made on the origin of the chinese boxing. Those researches pushed him to his famous trip around China and are probably the roots of his later teaching.
"To extend" (qiba) for beeing "one with the universe"
In this interview, the journalist is asking about the relashionship, numerous according to Wang xiangzhai's saying, between opera and martial art. The answer is the following (personnal translation) :
"In the ancient time, opera had ben created in order to educate the population. All martial art moves that are seen in opera find their origin in the way of boxing. At the beginning of the boxing, it was a practice called "qiba" (to raise up, to extend). This gongfu was a sort of shili consisting in the search of the force by the repartition of the bodyweight between the two legs and the right positionning of the head. By unifying the body in this practice, it was possible to extend it until to be "one with the universe". This gongfu was called qiba ( 起拔 ) and we can find it in nowerdays opera but mistakenly called qiba ( 起霸 / to extend for domination). It consist, then, in the searching of the right personnality of a caracter (the caracter's yi). By watching the postures and theories that are resulting from this practice, we can feel that without beeing very far away from the goal, they didn't reach it as well. They contain the original roots but did derive and they are, now, nothing else but esthetic postures created in the way to please the eyes of the rich spectator : They are a complete creation. There it goes today with the boxing practitionners : All are able to take different kind of stances but no one does really posses a real balance ability in their application. In fact, There are a lot of old horses but few young foal. All of this became fake distraction. And even in this way of doing, some will never acomplish anything. So how would they even more have any idea of the deep satisfaction that the way of boxing can bring to them ?"
Beijing opera (jingju) extracts from a representation of "The three kingdoms"
Later, in the same interview, he is expressing himself about the art of health preservation (yangshen) in those words :
"In fact, the keys to the health preservation are simple. Our deep human nature pushes us to simpleness and free of any restriction moves. The extention of natural instincts is its basis. Every day, in the fresh air of the morning, without any fixed method, simply bend all your body joints, consider the emptiness around you, move simply and freely. Feel the energy of the blood circulation in your body and in a meanwhile, be aware of the natural forces that are exerced on the outer part of your body. This is called : The spirit (shen) is as if swimming.
The body and the spirit are natural and confortable. Not only free and without any limit, they will progressivly extend to finaly be one with the universe."
The spirit is "as if swimming" by Wang xiangzhai
So, Wang xiangzhai's teaching, often presented in his most complex or martial aspect, had simpleness and natural for basis.