How to make someone disappear

My mother had loaned money to a friend. Now that friend is never home, nor does she return any phone calls. My mom is somehow suprised by this, but I've seen this happen before. Loaning people money tends to make them disappear. It's the one exception to the laws of matter and energy conservation. The Earth suddenly has 68 less kilograms of mass because this person who is debt to you simply no longer exists.
I wonder what would happen if I were to try this myself. Now, I get along swell with all the neighbors and all my coworkers. But the next time I have a feud with somebody who happens to have financial problems, I am going to try the following. I'll go up to them and say "Look, I know we had some differences, but I've been hearing that you've run into some tough times. Here's $50, you can pay me back in a couple weeks." Within two weeks this person will be gone. For %1 of the cost of an actual contract killing, I can be rid of the person.

After reading this, I bet there are some anarchists who are now tempted to buy US savings bonds. Don't do it. That is exactly what the Chinese are doing, and probably for the same reason. The ChiComms will actually make you miss the federal government.