The general tendency today is for Zen teachers to link Zen with more of their own modern understandings which, arguably, stray from the, predominantly, esoteric sermons of the older Zen tradition. Most notably they get it wrong when they try to handle koans failing to understand that they are a play off of function (用) and (體) essence or in the Pali canon, conditioned (more at constructed or composed) and unconditioned (i.e., nirvana). The whole point of koans is to get the student to awaken to the huatou (pre-word) which happens suddenly, when our mind becomes for a split second, unstirred, permitting us to see true reality as never seen before, beyond the ken of imaginal ideations (saṃjñā). This revealed reality is essence. Its expression in Zen such a shouting, speaking, laughing, etc. are examples of function. Think of essence as real fire and its expression as smoke.
I really can't blame today's Zen teachers especially those whose background is in Japanese Zen in which the stress is more on zazen than anything else. I also understand that the world we all live in has been almost totally hijacked by materialism as if to say, there is no underlying reality or ground beyond what our senses pick up and what we think (our imaginal ideations). But there really is. And the Zen teachers of old, some of them, directly intuited this reality or "stuff" (tathatā) from which even our thoughts are composed. Facing such a daunting barrier, the average person who wants to really study Zen, is going to have to learn to become more self-reliant.
Speaking for myself, I had to learn the hard way as did others. By this I mean one must develop faith in their own ability to distinguish between bompu Zen or pṛthagjana Zen (i.e., worldling Zen) and tathagata Zen which can only be described as being totally spiritual in a very real sense. Here is an example of what tathagata Zen is about:
"The object of Ch'an training is to realize the mind for the perception of (self-) nature, that is to wipe out the impurities which soil the mind so that the fundamental face of self-nature can really be perceived. Impurities are our false thinking and clinging (to things as real). Self-nature is the meritorious characteristic of the Tathagata wisdom which is the same in both Buddhas and living beings. If one's false thinking and grasping are cast aside, one will bear witness to the meritorious characteristic of one's Tathagata wisdom and will become a Buddha, otherwise one will remain a living being. For since countless aeons, our own delusion has immersed us in the (sea of) birth and death. Since our defilement has (already) lasted so long, we are unable instantly to free ourselves from false thinking in order to perceive our self-nature. This is why we must undergo Ch'an training. The prerequisite of this training is the eradication of false thinking. As to how to wipe it out, we have already many sayings of Sakyamuni Buddha and nothing is simpler than the word 'Halt' in His saying: 'If it halts, it is Enlightenment (Bodhi)'" (Hsu Yun Ho Shang Fa Hui).
The so-called "impurities which soil the mind" are native to us so that removing these impurities, even for a split second (which is all we have to do) proves to be a daunting task. For most people, their heart is not into such an onerous task because the path is not really a path in the usual sense of the word—at least not a path we can perceive. It is more about getting to the brink of not stirring up our impurities; or experiencing a distraction so profound as to, momentarily, stop the impurities. This distraction, in the example of Hakuin Zenji, can be the churr of a cricket or a timely shout.