I have an older Addy, and I dunked her for well over 24 hours. It was probably closer to 36 hours. I did not use the straightener on her though; I didn't want to ruin the texture, and I wasn't sure how it would affect her hair.
After the dunk, a shampoo and condition, I sectioned Addy's hair in very small sections with my fingers and used a wire wig brush, bottom up while holding the hair above firmly, to comb it out.
My Addy's hair is REALLY long, and it tangles easily at the bottom. I typically keep it up in braids to prevent it from becoming too tangled.
Now, my other Addy doll, who is new, is not as old. Her hair is pretty different, although I don't believe as soft as my mom's 1.5 year old Addy's hair. (I haven't had them together yet, and my mom will not take her dolls' hair down.) She was in excellent shape when I got her, so all she needed was a spritz and a quick brushing. Her hair is not as long-- and I even trimmed it to even the bottom up, gasp!!!-- and it does not tangle nearly as easily.
One thing I ALWAYS do with my dolls, and especially my textured-hair girls, is to spritz with conditioning or detangling spray. I really like Biolage's brand of spray conditioner, and in a pinch, the Walmart brand of Johnson & Johnson's No More Tangles is really good too-- and only 98 cents!
Here is an album of my Addy after the dunk. In the first pictures, her hair is still damp. Addy Album

Have fun with Addy! You'll want another soon, trust me!
Heather

<font color="#33CCCC" size="1">[ July 10, 2006 09:59 PM: Message edited by: jrtmom3274 ]</font>