It would be interesting to test out the Bolo rounds at some distance... say 25 and 50 yards. If the two balls are of slightly unequal weight, they might spin on a point between them and have some spectacular effects. The worry about the Bolo rounds is that it could very well cause amputation of limbs. In legal actions after the fact, this could land you in a serious legal situation.
The other rounds I've seen include
tear gas projectiles and tear gas projectors. The projectors simply disperse the tear gas agent at the muzzle. Just be sure of your wind direction. The tear gas projectiles look like a mini barrage balloon and deliver the tear gas on impact.
Most of the multi-size ball & buckshot loads are gimmicks.
There is a 12-gauge
flash-bang load too. Unfortunately it does it's work at the muzzle, limiting its usefulness. Especially at about $8 per flash-bang!
I could see uses for the "dragon's breath", tear gas and rubber ball/buckshot loads in crowd control or post-disaster defense. Use of these items when a mob of unfriendlies is approaching your house
may persuade them to look for easier prey. It'd be pretty nerve wracking to see a 60-ft spout of flame from a window or door, especially if one or more of your mob got hit with it. Then a follow up with a tear gas projectile that makes it unpleasant to be there might do the trick.
Rubber buckshot is good fired low into the legs or into the pavement just ahead of a mob so they bounce. The most cost effective seems to be Sellier & Bellot ($26.95) or Fiocchi ($29.95) at
Ammunition to Go -- for 25rds or about $1.20 per shell.