"Limericks are intended to give entertainment by making the listeners laugh. Part of that is to make the end syllables rhyme. Additionally, the words themselves even without their meaning should sound like its making fun of the subject. It is for these reasons that the priest changes the spelling of some words."
She changed the spelling of the words to make it sound like a different word even if it wasn't spelled correctly. For example: clirror is supposed to sound like clearer.
