Go get a tube ( a syringe actually) of roach bait gel. (Most supermarkets, drug stores or Home Depots have it).
This will ATTRACT the roaches to it, since they see it as food.
Put out little dabs or lines of it where you saw the roaches.
The roaches take the bait back to where the mishpacha is hiding and it kills them all. It may take a few days, but it works!”
We didn’t have this available when I needed it 25 years ago. The roaches crawl along the walls, so if you put Boric Acid along those wall edges, they WILL go into it, bring it back to the nest and share it with the other roaches. It is only dangerous if INGESTED. Merely touching it does not hurt you (l’havdil kind of like the Eitz Hadaas).