The thing about crocheting is that it's easy to snap a hair or two with a piece of metal and not even feel it when the hairs snapped/broken are inside the lock.
Yes, I do believe that it's possible, with great care and patience, to use a crochet hook to your advantage, but it's very likely that if it's used often that it will result in many broken/snapped hairs within the lock, weakening it significantly, with out you knowing about it until you find the lock has broken off completely.
At the end of the day, a crochet needle is a "short cut" and you know how they usually work out...
Hop a fence, land in mud, end up having to go around something, etc... Lots more work and doesn't actually save you any time, and may even cost you time and your pants with it!
Yes, there are exceptions, but they're few and far between.
With the crochet needle you're doing more work on your locks which feels natural to us folks used to needing to brush hair or fuss with it in any way to make it do what we want it to do, but it's not likely it'll help make the hair lock up faster, nor better, and it can get in the way of them doing what they "need" to do to form and mature naturally, meaning that the new growth will, in alllikelihood, be a "problem" until you've left it alone for several months, which will be hard because you're used to controlling your hair rather than letting it do it's own thing.
By the by, I did use crochet needle to tighten up my locks in the past. (I had an "excuse" but still!)
I too felt it didn't do 'em any harm... but I'm not going to do it again, and now that about an inch of fresh lock's formed at the roots of the old ones, I can feel the difference, even if it's been a lot of months and the locks have mostly recovered.
Honestly, I don't think one can ever really, fully undo the effects of the crochet on the texture and feel of the locks.
