The crux of the issue here is that a waifu is imagination personified. By definition, she is how you fantasize her, and this thought is aided in taking form through a personality set forth in the original source material she came from. The healthy man knows he is imagining his waifu, and accepts this.
Definition of lye. 1 : a strong alkaline liquor rich in potassium carbonate leached from wood ashes and used especially in making soap and for washing; broadly : a strong alkaline solution (as of sodium hydroxide or potassium hydroxide )
Lye is an alkaline solution that's used for cleaning. If you were a maid about 200 years ago, you probably cleaned the chamber pots with lye. Lye is an old cleaning product and an old word too. It comes from the Old English lÃ©ag, which is related to the root for wash in our word lather. Lye is still used to make soap, but you probably won't come across the word except in old novels.