Though the Luggnaggian king wishes Gulliver to stay in Luggnagg, Gulliver insists on leaving and so the king sends him off with riches and a letter of introduction to the Japanese emperor. Upon arriving in Japan, Gulliver pretends to be Dutch and asks the emperor to help him find a Dutch ship leaving from Nangasac. He also asks the emperor’s permission to excuse him (out of respect for the Luggnaggnian king) from the Dutch maritime custom of trampling a crucifix. The emperor is suspicious of this request, wondering aloud if Gulliver might not actually be a Catholic. Nevertheless, he complies.
By orienting the (imaginary) country of Luggnugg in relation to the (real) country of Japan, Swift lends Gulliver’s adventures verisimilitude, making it seem like Luggnagg is actually a place any reader could potentially visit, just as they could potentially visit Japan. Gulliver adds lies upon lies by pretending not only that he is Dutch, but that he has made a specific promise to the Luggnaggian king.
Gulliver sails back to England on a Dutch ship, successfully convincing the sailors that he, too, is Dutch. When pressed about whether he’s trampled his crucifix, Gulliver answers that he’s “satisfied the emperor and court in all particulars.” The voyage passes smoothly and Gulliver returns to Redriff in England to see his family after being gone five years.
Since Gulliver has been so comfortable about lying to the Japanese emperor, it’s curious that he doesn’t seem to feel that same comfort now and uses evasive language to avoid the outright lie of saying he’s trampled the crucifix.