I bought a old flat with bugs problem and find this works best(*least effort). What I do is stick "housefly trap" (yellow flat sticky paper trap from Daiso, 5pcs in a box) at bugs commonly seen area. It work like a talisman and stick all the bugs. Over time the number will reduce / controlled. Sometimes it will also stick unwanted lizards & cockroaches in the house. You can choose a hidden view area to cover the unsightly view of dead bugs bodies stick on the trap from guests. However you may need to change this "talisman" weekly. My 2 cents worth.
