Works well, adds a very simple expiry date option to your posts.
The only thing I would say to improve it would be to make the date/time selection a little clearer - eg. drop-downs selectors rather than text based, because it would just be a little simpler to input the expiry date. Also maybe call the block 'Expire' rather than 'DishSoap' as that is easier to explain to clients.
But overall a really nice plugin and would use again.