I have some direct knowledge of less than lethal munitions. We JUST switched to 40mm after 20 years with the 37mm, so i trained with the 37mm Multi Munitions launcher for 20 years, very simple, easy to use single shot. The older revolver styler were driven by a rubber band that broke, so we ditched them.
LTL is called that because it still CAN be lethal, never ever call them NON lethal. A 37mm baton round to the brain housing group can cause a lethal injury, for instance, which is why we fire into the ground directly in front of the target to skip them UP into the knees, hence the affectionate nickname, "knee knockers."
Shotgun LTL is suspect AT BEST. Beanbags can work, (know of one that worked from a tower quite well), but inaccurate at any real range. We discovered that the 60 caliber "stingballs" are worthless, shaped like little rocket ships, and fly like Flash Gordon is driving. The ONLY thing we use in a 12 gauge that is LTL is Number 7 steel, (so it shows up on X-Ray), fired at the lower extremities between specified distances but never closer than 20 yards. If being closed on, the rounds CAN be fired center mass, and are then considered lethal force.
I gun shop I worked at MANY years ago sold rubber buckshot once, until I convinced them to pull it as a bad idea. People are stupid and will try this stuff out on each other in drunken parties, "Dude, it's RUBBER, it's safe, lemme shoot you!"
Want to do LTL? Use good pepper spray. I highly recommend Phantom - it's like the Devil's own farts.
Do NOT use pepper ball launchers - in the several times I have seen those deployed, the only people they irritated was us walking through the crime scene later and stirring up that synthetic "OC" into our eyes while doing reports.