For years we've had silverfish darting around our guest bathroom. I bought some silverfish traps (little cardboard boxes with sticky goo to ensnare them) and they helped, but didn't stop them.
A few weeks ago I read that lavender oil is a good silverfish repellent. It's only $5.59 for a small bottle on Amazon, so I decided to give it a try. I wetted the end of a Q-Tip with the oil and ran it around the perimeter of the bathroom floor, adding a little extra to a seam between the floor and the wall. It smelled nice and we have not seen a single silverfish since. I'm going to wait and see how long it takes for them to come back, and then create a maintenance schedule.
Image: ACC1/Flickr
