Washing a wig in hot water won't straighten it; to take curls and such out, you need to put it on a wig head on some sort of stand so the hairs aren't against the floor or such (I stick shorter ones on the plunger in the tub), and pour the water over it. For the back of the neck you'll need to clip the top layers out of the way (if it were a longer wig I'd say "or hold", but you'd probably scald yourself doing that on a short wig) to make sure you get them straight.
Originally Posted by Moofingham
There is a vibe here that says "We're in this together! Through thick and thin fabric! Through cold water washes and burning hot irons! Though we might super glue ourselves to our projects, cut holes/gashes/oh-god-mom's-gonna-kill-me into the dining room table, we will stand strong together. Unless there is a 75% off sale at the Fabric store. Then you're on your own. And get the hell out of my way." <3