It's really not a good idea to scare your cats.

Cats are territorial animals and your house is their territory where they need to feel safe because they are stuck with it.

An unsafe territory can lead to worse behavioural problems. Plus it's not good for the cats seeing the above.

Put yourself in their (very small) cat shoes. Would you like being scared in your home, the one place that is supposed to be your sanctuary and safe spot?

I know this is not the manly man solution you are looking for, but I would look into rather buying or making programmable cat toys that would divert their attention away from the area where you don't want them to be at night. That would keep them entertained and happy and it would solve your problem too. Moving feathers or toys, lasers, catnip etc...

Restricting access to that area can also be achieved by placing a sticky tape or aluminium foil mat in their way, they won't like to walk over it and will go play somewhere else of their own accord.

Use your force for good, OP, you got this!