Did he mean #4 buck? IMHO I want something to cut the central nervous system in case of PCP or Meth user. Birdshot at close range will cause massive soft tissue damage but that might not mean an instant stop. #4 or #1 Buck will penetrate to the spinal cord but not overpenetrate within a neighborhood causing injuries to innocents.
00buck is good for cops because they might want to penetrate car doors, home doors and/or walls. For home defense 00buck is probably overkill.
Many moons ago I read an article by a "white hunter" type who guided big game hunts. He was the "backup" to take out the game in case the prime hunter missed. He said the best was #1 buckshot--better than 00. I believe he was talking about jaguar hunts, but it was certainly one of the big cat breeds as the game.
BBB shot, 3”, 12 GA (of course) creates huge holes of hamburger at 15 yards.