Collins employs hyperbolically exaggerated language in Miss Clack's diction. In doing so, he is satirizing the self-important speech of prosetylizers in his period. In Chapter 1 of Narrative 1, Miss Clack "humbly" explains that she's only helping with the Moonstone case because she's being paid:
Pecuniary remuneration is offered to me—with the want of feeling peculiar to the rich. I am to re-open wounds that Time has barely closed; I am to recall the most intensely painful remembrances—and this done, I am to feel myself compensated by a new laceration, in the shape of Blake's cheque. My nature is weak. It cost me a hard struggle, before Christian humility conquered sinful pride, and self-denial accepted the cheque.
In this passage, Collins lampoons Miss Clack's apparently Christian attitude. Her protesting language only underlines the hypocrisy of her actions. In order to feel all right about taking money for doing a good deed, she needs to justify her "struggle" to accept "pecuniary remuneration." She does this by reframing it as "Christian humility" to herself and to Franklin Blake, the intended reader of her "Narratives." Clack protests a great deal but eventually takes the cheque from Blake, as she clearly doesn't really intend to turn it down.
This is really self-interest reworded as a "hard struggle" for "self-denial." Miss Clack is un-self-aware enough to apparently believe that her exaggerated, hyperbolic self-criticism and "reflection" covers up the self-regarding reality of her choice in this passage. Collins implies that with enough bluster and self-deception, even the most banally selfish or money-motivated choices can be framed as Christian behavior.
Clack's hyperbolic hypocrisy doesn't just extend to excusing herself. She is horrible about other characters—particularly Rachel Verinder— in a very overt way. However, because she can't see herself clearly, her discussions of them are also delivered as moralistic tracts meant to persuade the reader of her wisdom and her moral righteousness. Similarly, when she admires someone, they are also described in naively hyperbolic language. In the same chapter, she begins to call Godfrey Ablewhite the "Christian Hero," going on to describe his mugging by the Three Indians in the terms of a Christian parable:
When the Christian hero of a hundred charitable victories plunges into a pitfall that has been dug for him by mistake, oh, what a warning it is to the rest of us to be unceasingly on our guard! How soon may our own evil passions prove to be Oriental noblemen who pounce on us unawares! I could write pages of affectionate warning on this one theme, but (alas!) I am not permitted to improve – I am condemned to narrate.
Clack's description of this "pitfall" is nothing short of ridiculous, especially as she uses the example of Godfrey being attacked and searched as a cautionary tale. She aligns moral vigilance and being "unceasingly on our guard" with avoiding being "pounced" on by "Oriental noblemen," a ridiculous comparison in any context. She then goes on to immediately deny she's speaking moralistically, as given the terms of her contract with Blake, she isn't "permitted" to "improve" others and can only "narrate." Collins's satire is painfully sharp here. Clack can't seem to tell that this plain and scientific "narration" she believes she is "condemned" to writing for Blake has already become a pompous and moralizing screed.
Collins satirizes what he viewed as ridiculous behavior by Christian fundamentalists in The Moonstone in many ways. One that recurs often is the motif of Miss Clack's distribution of useless, evangelizing pamphlets. When she comes to the Verinder house to see her aunt Lady Verinder in Chapter 1 of her First Narrative, Miss Clack leaves Rachel a pamphlet by "dropping it through the railings":
I sat down in the hall to wait for my answer – and, having always a few tracts in my bag, I selected one which proved to be quite providentially applicable [...] the blessed consciousness of returning good for evil raised me quite above any trifling considerations of that kind. The tract was one of a series addressed to young women on the sinfulness of dress. In style it was devoutly familiar. Its title was, ‘A Word With You On Your Cap-Ribbons’.
Pamphlets accompany Miss Clack as a motif, even though no-one ever reads them. Through this, Collins implies that information on things like the "sinfulness of dress" is not actually "returning good for evil," but actually just spreading nonsense and overly devout misinformation. Clack's self-righteousness and silliness here are pointedly exaggerated. Even the title of the pamphlet itself—which is "devoutly familiar" to Clack—is a ridiculous one, as "cap ribbons" are a foolish thing to call "sinful."
Clack doesn't think much of Rachel's morals, but the reader isn't encouraged to think much of hers, either, in moments like this. She also seems to be the only one reading these tracts, as they are always turned down by people she tries to pass them along to. Penelope refuses to take one in the First Chapter of the First Narrative, and Rachel also refuses to read "Satan Among the Sofa-Cushions" in Chapter 4 of this Period, when the pamphlets make another appearance.
Collins satirizes the hypocrisy of Christian fundamentalists repeatedly in this book, using Miss Clack as a mouthpiece for their pious self-interest. This character speaks in the hyperbolic and overblown tones of a fundamentalist religious tract to her reader in the first Chapter of Narrative One:
Thoughtless and superficial people may say, Here is surely a very trumpery little incident related in an absurdly circumstantial manner. Oh, my young friends and fellow-sinners! [...] Oh, be morally tidy. Let your faith be as your stockings, and your stockings as your faith. Both ever spotless, and both ready to put on at a moment’s notice!
I beg a thousand pardons. I have fallen into my Sunday-School style.
The "Sunday-School style" of this speech reads as being unbearably patronizing and high-handed, especially because Clack begs an insincere "thousand pardons" and then doesn't stop preaching. All of Clack's language is exaggerated and overblown, as she exhorts people to be "morally tidy" in their behaviors. In this passage, Collins pairs weighty Christian ideas like moral purity with seemingly trivial ones, like "tidiness." The self-evident silliness of these duos reflects Collins's low estimation of people who held these opinions.
The use of chiasmus in this passage also adds to its hyperbolic quality. Chiasmus is a a rhetorical figure often used in religious texts, where words are repeated in reverse order, as when Clack says "let your faith be as your stockings, and your stockings as your faith." With this phrase, Collins employs another ridiculous juxtaposition of a big, important thing with a small, silly thing, in language that sounds almost Biblical. This chiasmus is central to the satirical work of this passage, as it shows the hypocrisy of the self-important and persnickety Miss Clack's views. Collins was publicly critical of what he viewed as the hypocritical and pompous behavior of people who preached evangelical Christianity in mid-19th century England. If people like Miss Clack can put on or take off their "faith" as easily as their stockings, Collins implies, their moral "tidiness" is probably not as "spotless" as they believe.
