I keep an index card under my laptop for the ones I use regularly, I was feeling too lazy to look it up yesterday. Thanks, Taxy! I've added it to my card.
PF, I think your suggestion of using the upside down question mark, ¿ at the end of a rhetorical suggestion would be a great way to indicate that it is rhetorical and is not expected to be answered.
It would save people d.from getting the wrong impression