Ok Mr. Carter it sounds like what you need is a demon removal charm. As a professional devil myself i know exactly what to do, so listen carefully. There are multiple different charms but this one seems to be the most affective towards different types of demons:
First, mix yeast and salt into a cup of warm water (warm not hot) and wait for about five minutes until the top of the mixture bubbles. In a bowl add flour and your previous mixture, and stir. Kneed the flour yeast salt and water mixture until it forms a dough and for a bit longer afterwards. Now, dust a baking stone with flour and cornstarch and kneed the dough into a flat circular shape, add tomato sauce, cheese, and other edible charms before throwing it into the oven until the bread is toasted and the cheese is gooey. I’d even recommend asking a yankee down in nyc if you need help. Eat it for dinner before you go to bed for max effect.
Now, when the demon comes to visit you in the night, splash them with a bottle of bleach.
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I'm not quite sure bleach would sufficiently ward off Nyarlathotep, and what am I to do with the pizza? It's rather strong for my tastes, though I do love a good cheese.