When you enter the town, kill everyone. When the second wave of people arrives, also kill all of them. You can then go into the house and they will not come out. Additionally, during the mine cart section of Chapter 4-2, the mine car will stop and lots of enemies and two chainsaw men will load into the stopped cars. To avoid most of this encounter, be in the front car and immediately shoot the switch. The cars will start moving, and you will have only have about four enemies to kill.