You can bug bomb spiders, but the ingredients used in these products work as repellents for spiders, causing them to move to deeper hiding places to avoid the spray, so they normally do not die. The active ingredient in most bug bombs, pyrethrin, is rarely lethal to spiders.
Bug bombs bring other problems with them. Manufacturers recommend emptying cabinets and opening their doors and drawers to allow the fog to penetrate deeper into the space. Once the bomb is finished its spray and the room has fresh air, the owner faces the task of cleaning countertops, tables and other areas covered with the spray. The University of Kentucky recommends using a different approach to eliminating spiders.