i could see loading up some shells with rock salt as a marginally more humane animal deterrant, instead of flat out shooting them. youd have to test them to see what ranges they are nonlethal at. there are some older members on GCN that can give you a firsthand account of what its like to be shot with rock salt, might want to ask them for some clarification
breaching rounds are made from compressed/sintered or wax/resin-encased powdered metal that disperses after it transfers its energy to the lock/door hinges/target so that you eliminate the danger of a ricochet or penetrating a dozen walls like shotgun slugs or buckshot might.
i suppose if youre set up for reloading shells you could even make your own beanbag rounds

i can just see the look youd get from your wife/girlfriend after asking
'honey, can you make a bunch of tiny little beanbags for me?'
if you ever shoot/injure a person with these though i hope you are prepared for an extended vacation hosted by the Canadian penal system.
the beanbag rounds police use have a little flag sewn to their ass or have an empty 'tail' to stabilize them in flight.
ive even seen pieces of dowel

eek

used in some countries as a 'less lethal' round. there are pics on several protest sites of protesters shot by cops with 'nonlethal' ammo and its pretty brutal stuff. theres one pic of a young girl that was shot in the face with one and it looked horrible.
some part of me thinks that even though they are specifically warned to only shoot 'less lethal' rounds at extremities and never use them at point blank or very close ranges, cops often do so and aim for peoples chest and head deliberately.
these 'hornet's nest' rounds full of tiny rubber balls look particularly painful and aptly named: