Ooh, I've had a few of those this year, if I'm thinking of the same thing you're describing. A friend of mine calls them "prehistoric" because they do look rather ancient. Had no idea they stank, though--eww. Glad to do the glass-and-index-card method, then, to be rid of them. One scared the snot out of me the other week when it did a flyby of my arm while I was at my desk, and it took forever to get it!

Generally, if I can, I'll trap them and put them back outside. I'd want the same to be done for me. If I don't have a choice, I'll squash them, but I hate to clean up the mess.