You could try diatomaceous earth. It absorbs their oils and dries them out. It can also pierce their shell which speeds up killing them. Its not harmful to humans as far as I’m aware. Could also help keep the kitchen dry.
I think that is a bit of a myth with DE. People seem to use it also for ants etc thinking it somehow dries them
Think of DE as very very tiny razor blades. M y insects have soft spots in their joints. This literaly get stuck in said places and cut them up. Stronger bugs may start to heal but if keep one keeps healing and getting cut one gets crusty. Maybe thats where the dries them.up thing comes from?
DE does kind of work but only in a direct contact kind of way. But if you have isopods in your huse its almost always due to damp rotting material. This isnt good if your house has a lot of wood as it means you no doubt have fungal issues. Unlike the literally harmless peaceful isopods, fungus will destroy your wood, make it steuctually unsafe, invite many more pests (like ants and termites to name a few) and the spores are often considered unhealthy. Drying out the house is the easiest and best long tetm sollution then all of the above issues take care of themselves. Who knows, a ditch channelling runnoff water away from the house might be all that is needed. A very easy task sometimes.
Post pics if you like and we can all put our heads together