Please can anyone give me herbal advice how to get rid of unwanted guests cockroaches !
If it is in a dry area I would suggest unrefined diatomaceous earth (DE). DE is the skeletal remains of phytoplankton containing 80% silica. The silica is like glass shards to insects. It will scrape their waxy coatings off causing them to dehydrate in a few days. If they eat any of it it will cut up their insides killing them. It des not work wel thoug if it gets wet, so it is best used inside or in dry climates. Use the unprocessed DE from plant nurseries. The processed DE for pool filters will not work as well. It is relatively safe for humans and pets. If ingested it is not toxic, though you do not want to inhale the dust or get it in to your eyes. It is good to spread around dark, hidden areas like inside cabinets, under the stove and refrigerator, etc.
Boric acid is also good, and I have heard baking soda is also excellent. Though you need to mix them in something the roaches will eat.