I've been looking all around my house for something to use as a bump hammer. I've got many things to work out great but I've been looking for something that I could carry around with me or that I could find anywhere. I failed in the sense of finding something for me to always have on hand but I did make a discovery.
High Heel Shoes are perfect bump hammers. They can't be the pointy ones, they have to be flat on the bottom. The weight of the heel is perfect for bumping, and the sole is usually flexible and gives you a good swing. I've used the shoe on Schlage, Weslock, and Kwikset and have been able to bump them open within 2 tries. That's the best I've done with any object.
For us guys I do have some good news, I tried using the heel of a normal tennis shoe with some success about 5 or 6 tries. Although I did get good results by sticking a heavy rock into the shoe towards the toes and holding the shoe by the heel and swinging. The only problem is that it's hard to find the right sized rock or heavy object and if your shoe is too rubbery it wont transfer the energy as well.
So I guess for us guys it's back to the drawing board.