Is there any way possible to kill spiders and silverfish with the same thing?

A chemical free way to chase away, (not kill) Spiders is to place Hedge Apples or pieces of Hedge Apples wherever you see spiders. Spiders hate these things. You can not find the Hedge Apples until late summer/early fall but that is when the spiders are at their worst. Also, do not kill the Granddaddy Long Legs, they are lethal to other spiders and bugs but not to humans.There are plug-in devices that create a "barrier" in your walls and emit a high-pitched tone that bugs run from. They sell at Sam's Club for $20 for a package of 3; I've also seen them at Wal-Mart. They work! I hate spiders and our new house was loaded with them until I got these. It takes about a month to get rid of them all.To keep silverfish and firebrats away, keep basements, laundry rooms, and bathrooms, especially shower stalls, clean and dry. Plug or putty holes or spaces around pipes. Repair leaks and drips in Plumbing. Clean out closets periodically. Collections of magazines, papers, and books provide food for them. Occasionally, move books around in a bookcase. Keep foods in containers with tight lids.