Okay, so my idea is as follows.
It's a clothes dryer, but it doesn't require a power source to operate, and does not dry clothes. If any clothesare placed in it, it will not run a cycle. However, if it is empty and turned on, it will run a full cycle, and will be impossible to open until it is done. Upon finishing, the dryer will contain a random number of socks, no identical pairs, of a type and number determined by the setting.
This part is an optional add-on, not sure how I feel about it. If pairs of socks are put in and it is run, nothing will happen. However, if single socks are put in, once the cycle is finished the sock will be accompanied by it's matching sock. This sock is shown to have disappeared from wherever it was and reappeared into the dryer, by unknown means.
Comments/criticism very much appreciated, especially regarding whether it should be a Joke SCP or not.