And this is one of the dumbest off hand suggestions I have seen in a long time!
If someone doesn't know better and thinks you are serious they could throw them into a fire and cause injury.
Yes, ammunition could be destroyed by burning, but in a proper container to contain the shards of brass and stuff that will fly around. Done by someone who understands what they are doing, OK, but not based on the dearth of information provided.
If you can, break it down, or give it to someone who can break it down. Don't throw it into the garbage, or a fire.