Recommend a simple method to the landlord: to use cockroach medicine, you must draw a few circles on the pubic hair like chalk (available in major shopping malls).

Advantages: convenient use, quick effect (only one day), and no side effects have been found yet. In fact, the biggest advantage is that you don't have to make faces in the hospital, hehe.

Disadvantages: There will be a slight burning sensation in the genitals after one day of application, which can be washed with clear water immediately.

I've been there myself, and I hope I can help you.