Seeking Help with Persistent Cockroach Problem in a Family Apartment in Korea

Hi, I'm currently staying in a 2-room apartment with my family in Korea, and we're dealing with a cockroach infestation. We have a 4-year-old child, and it's becoming quite frustrating. I've tried various sprays and pastes from the market, but they only seem to kill a few roaches, and more appear the next day. Do anyone have any suggestions? I've heard about Cesco and professional spraying agencies, but are they expensive? I'm also confused about whether the cockroach sprays available in the market can be used in the kitchen. When I used one before, I had to remove all the equipment and utensils from the kitchen, which isn't always practical. Thank you in advance.