I’d be hesitant to use a “homemade” round for home defense. Even using conventional reloads is District Attorney bait in the event that you actually have to defend yourself. 00 or #4 are both good bets. Federal markets a reduced recoil 00 buck load in their “Ranger” lineup that is a great option for home defense. Bird shot is a bad choice-penetration is very low. It produces grotesque but shallow wounds that don’t readily incapacitate the target.
I have a few boxes of that but have never tried it...funny they label it as "Power Shok"
I don't care who you are, 12ga's hurt to fire.
12 Ga Federal Law Enforcement Low Recoil Tactical 00 Buck & Federal Law Enforcement Low Recoil Tactical Slugs are both available and great home defense rounds. These can be had either in Low Recoil or Standard Recoil, but the kick is somewhat more with the Standard shells. The local Sheriff’s Dept has gone to these Low Recoil shells. The punch is still there for home defense or for most law enforcement needs. Muzzle velocity is a couple hundred fps less with the low recoil rounds.