I haven't tried filtering at all. (For reading. I have used posting filters a couple of times.) It makes me twitchy, but I suppose it might come to that. Though I think I might spend more time obsessing about who's on the filter than I save by reading it.

I do! I totally have a snowball in my freezer, that I made from my windowsill on the Day of Blizzard, and expect to keep until I can throw it at someone this summer. Or, more likely, totally forget about until I go to make a snowball and freeze it *next* winter, and find one already there.