I have to sweep the house in preparation for a surprise house guest, so I put the cat in the bedroom with my husband, who is still asleep, and closed the door. Molly is deathly afraid of the sweeper, and I'm hoping his proximity will calm her. I have never figured out how to assuage her fears of the vacuum cleaner. She wasn't afraid of anything when she was a kitten, but as she grew up the sweeper became her major nemesis. I once found her hiding under a skirted ottoman after I cleaned the house, and let me tell you, how she crammed herself under there I'll never know. She's a big girl.
Animal trainers tell you to associate a good thing like a favorite food of your pet's with a bad thing like a sweeper so they will transfer the pleasant feelings from the treat to the sweeper and displace the fear. That might work with a food-oriented dog, but I have never seen a cat eat when it was upset. Cats must have a better sense of priorities:
"You're giving me a treat. Are you insane? There's a kitty killing machine rampaging around the house. Right now I have to hide. Get out of my way. I might have a bite later."
And dogs? "What's that big noisy ---SNACKS!"
I have serious doubts about anything that can be distracted from danger by a Pup-a-roni.