Toxins
My friend’s mom was a huge germaphobe. So she kept bottles of hand sanitizer and a stack of napkins by the door, and you had to use them before entering the house. If you didn’t, she’d close the door in your face.
Also, she required anyone who wanted to pet her dog or cat, you had to brush them before and after to help “diminish any harmful human toxins”. Story credit: Reddit / ForgingHephaestus