In the early days, we were both out leafleting and I suddenly heard a scream from my other half who was stood with his hand in a letterbox attached to a dog on the other side!
There are some that bark like crazy and hit the door with a force to make the house shake and other silent ones with jaws waiting for a finger to reach an inch too far!
Better the leaflet is a little crumpled than your flesh.
Keep at it & Good Luck,
BFN