I've been doing this for... most of my life actually. It does take forever to dry - almost 2 days, unless I let it partially air-dry loose first. I get better (more stretched) results with cloth strips than with elastic banding. It's not so much for "straight" hair but for stretching the hair to have fewer tangles and less shrinkage. My hair is hip/tailbone; when I do this, it only shrinks to mid-back... as opposed to the usual shoulder length shrinkage. My daughter has a looser hair texture than me, and on her hair, it does initially come out almost as straight as blow-drying, but it does not stay straight as long as blow-drying. I've also used this method on relatives with tighter curls, and it worked just as well. Smaller sections are key if you don't want the hair to be too poofy, but the most important thing is letting it dry completely.