You can get this achievement without really trying for it over time but this bit of advise might help.
Get them down to 2. Slug them and figure out where the hatch is. Hook the one closest to the hatch and close immediately.
Then, if I could, I usually let the other one go.
Also, if someone happens to pop out using a key you can possibly get two hatch closures. I had this happen once to me while going for this achievement. 1st guy died, 2nd guy jumped the hatch which i closed. And then killed the third guy and closed the hatch again.