What's the nastiest or strangest thing you've ever pawed through; what are the greatest lengths you've ever gone to try to find or retrieve something of monetary or sentimental value that you've lost?

I’ve misplaced my mouth guard. It’s a relatively small, clear plastic thing that represents over $300 in dental services. I’ve already looked everywhere I can think of and looked through all the trash and garbage, and that was not all pleasant; as you can imagine, because I just couldn’t stand the idea that the damn thing might have fallen into a trash can and I could have thrown it out. It just made me wonder what other people may have done to try to find or retrieve things of value.