Silverfish love damp/humid places like bathrooms and basements. They also live off sweet/starchy things, like soap scum (yummy!) and paper. To get rid of them make sure damp places in your home are well-ventilated and get a sump pump if you can. Tidy up and get rid of all the nooks and crannies and crumbs lying about - they love clutter. I've never heard of silverfish hitching a ride on someone's clothing before, but you may want to wash your clothes again but without fabric softener, since it leaves a sweet residue behind on the fabric which will only attract them. Look around for any cracks, gaps and hiding spaces and be sure to block them up with something they can't eat, like silicone caulking. You can also but borax powder in their hiding places before sealing them up, but remember that this is toxic and not safe around pets and children so be careful. If you have a collection books like I do, wrap them up in a plactic bag (as air-tight as possible) and put them in a freezer for a week or two to kill any adult silverfish that might be feasting on your literature. Good luck!