In a recent post, I discussed Ivanhoe's (The Sense of Antirationalism) treatment as parodies of those passages in the Zhuangzi that refer to what are clearly meditative practices. In other words, he does not advocate for the practices, but sometimes simply uses them as a vehicle to present his own ideas, and other times might actually make fun of them. As I said previously, I am a bit wary of the word 'parody' in this regard since it would seem to suggest outright dismissal. Still, it is difficult to come up with another.
With respect to the "fasting of the heart-mind" passage (Chapter 4), Ivanhoe refers to an article by David Nivison (Hsun Tzu and Chuang Tzu) in which he states that this is a direct parody of Mencius' "flood-like qi". When asked how he excels, Mencius replies "I am good at cultivating my flood-like qi." (Mencius 2A2) When asked to explain, he says it is "in the highest degree vast and unyielding". Why "unyielding"? Because it is essentially moral ("It is born of accumulated rightness."), and to cultivate it, therefore, is to obey one's conscience; it is to become good. Moreover, "you must work at it and never let it out of your mind." This is certainly an interesting path to follow and might, for all I know, lead to a happy and fulfilled life, if somehow the oppression of guilt that is its shadow could somehow be obviated. But it is essentially the opposite of Zhuangzi's point of view.
Thus Zhuangzi creates a story in which Confucius advocates a path that, instead of "never letting it (qi) out of your mind", finds it beyond and only after fasting from the mind. And it is a qi which, instead of being "unyielding", "waits upon all things", that is, is utterly and completely open. He turns Mencius on his head, and we could call this parody. As such, it is not necessarily an advocacy for some method of realizing qi and Dao, but simply a vehicle for explaining his position. Yet, at the same time, it does present an opportunity for imaginative meditation since it suggests an experience inherent in human experience (just as Mencius' conscience does).
Because he is a Confucian, Mencius' Dao is a moral Dao. What he is thought to have done is to render Confucianism more mystical. This was later picked up by Neo-Confucianism which, in the context of the mysticism of Daoism and Buddhism, felt the need to answer this human need for mystical connectedness. Were any of these philosophies successful? If we are looking for a country full of sages, then the answer is decidedly, No. But if we look at it from the point of view that might ask if the eradication of smallpox impacted civilization, then we might answer, Yes. This latter may not be so easy to identify, its ameliorative effect being diffused throughout society, but it is real, nonetheless. But the real question for Daoism is focused on the individual, not society. Can any of these philosophies lead you to a happier life? Daoism believes they can; and recommends itself.
You can check out Scott's writings on Zhuangzi here.