What an epiphany!
It took me a little while to figure out how to thread those skinny, skinny wires through the edges of my piece, but once I did ... Wow! It was a breeze to block, a task I usually hate. Four wires, a few T-pins, a spritz of water, and the next morning I've got the most perfectly flat, squared off piece of knitting. I am definitely a convert.
The piece is actually finished - buttons sewn on and everything. One more piece checked off of my Etsy list. No photos of the finished piece yet, 'cause I'm hoping my sister will drive over today so I can rope her into modeling it for me.