The OP says that her dog is afraid of the vacuum and runs and hides. This is not a dog that barks uncontrollably at the vacuum. I think something like the ultrasonic collar could be worst thing you could do for a clearly fearful dog.
I am no trainer, but I think your best option is to crate with treats when the vacuum comes out. Depending on how fearful your dog, maybe you don't even need to crate and can give the kong on a dog bed or in another room that you're not vacuuming. A treat dispensing toy could work as well.
This way when your dog sees the vacuum it may start to associate it with something positive (food) and might actually get excited when he sees the vacuum. You can probably also use this for your dog that herds the vacuum. That's what I do with my dog. I give her a treat dispensing toy and she can care less about the vacuum. These positive association can take a few times for your dog to get it.
