> However, some say that homemade garlic-infused oil can develop botulism if stored at room temperature for more than four days. To prevent this, you can sterilize your jar and refrigerate the oil as soon as it's made
I.e. the "infuse" step where it says "Seal the container tightly and let it sit at room temperature for a week." No. Never. This is basically how you deliberately grow Clostridium botulinum.
It's like if it gave you a recipe for C4 to use as Play-Doh with a caveat at the bottom "However, some say this homemade Play-Doh may explode violently, so be sure to keep it away from any matches."