John Collier's story can be read in both literal and metaphorical ways. The reader could accept it as a story of a young man who wishes to buy a love lotion; this is plausible, but it makes the story resemble a fairy tale or locates it in earlier times, as stores selling such things are hardly modern. Similarly, the reader can, at a stretch, accept the conversation between the two men. The old man cynically encourages his young patron to think ahead a few decades and imagine killing his wife. By then, the young man will be older and wealthy—and the old man's shop will still be in business, able to sell the potion for an exorbitant price.

An alternate reading treats the story as a fable. The young man can barely imagine himself happy, even in the short term. He doubts his ability to make the girl love him, so much so that he imagines tricking her with magic. This seems an unlikely basis for future wedded bliss. His vision of marriage is not positive. He imagines, through the old man's words, feeling trapped by the wife's demands—so much so that the only outlet he can imagine is murder. The "potion" that will free him is magically undetectable. The high cost of the potion, in this reading, is that it is unattainable.

It's more expensive because it's illegal. What the old man euphemistically refers to as "life-cleaner" is actually a deadly poison designed to be administered without leaving a trace. That's what makes it so valuable; it's essentially a do-it-yourself murder kit, which the old man knows from personal experience will always be in great demand. The old man is taking on a big risk by selling this deadly poison, so he needs to make it worth his while financially.

The demand for this unusual product tends to be from men a lot nearer the old man's age than his latest customer, young Alan. Only once men have become bored with the endless devotion of wives and girlfriends enchanted with love potion will they darken the old man's door once more to get their hands on some of his finest "life-cleaner." As well as being older and wiser, these men are also likely to be richer.

The old man in the story uses the terms "glove cleaner" and "life cleaner" as euphemisms. Obviously, he doesn't want to use the word "poison" too openly, so he uses circumlocutions to hint to his customer that he might want to use something to get rid of his beloved in the future. The reader learns in the course of the narrative that the love potion only costs one dollar, while the "chaser," the "glove cleaner" or "life cleaner," costs five thousand dollars. The old man is confident most of the young men who buy his love potions will be back to buy his poison at some time in the future. He explains to Alan Austen:

"I look at it like this," said the old man. "Please a customer with one article, and he will come back when he needs another. Even if it is more costly. He will save up for it, if necessary."

"And how much," said Alan, "is this wonderful mixture?"

"It is not so dear," said them old man, "as the glove-cleaner, or life-cleaner, as I sometimes call it. No. That is five thousand dollars, never a penny less. One has to be older than you are, to indulge in that sort of thing. One has to save up for it."

In other words, the old man makes all his money off the poison, and his young customers who buy the love potion will not be able to afford that lethal "chaser" until they have reached middle-age. The old man obviously has a very cynical view of love. He seems to believe that love leads to marriage and marriage—for many people—becomes so unpleasant that they will do almost anything to get out of it.