In all my research I couldn't see anywhere any reference to steeking crochet work itself, though it sometimes plays a part in knitted steeking. I'm sure I'm not the first person to want to do this in crochet and I'm sure I won't be the last. So after a bit of playing around, and a few disastrous attempts, I came up with a technique that worked. I have no doubt that others have used steeked crochet work before and I'm sure there are other ways of doing this, some possibly more successful than my own, and I would love to hear of any you've come across. But for now this is what I did, I've set up the tutorial in a PDF to download if fancy having a go. Have a test run first, the most important thing about doing it this way is to make sure you only work through the front loop of the stitches either side of the steek section, as this is what will ensure your end will catch when it is cut.
I've written the tutorial in double crochet (single crochet if you're using US terms) but it will work in half treble and treble too. I've written it so that the opening is at the beginning of you your work, but you can just easily add it in half way through, close it up again (perfect for thumbholes) or leave it open to create an opening at the end of your work.
I hope to work on a pattern using this technique to self publish in next week or so. Enjoy and if you have any questions feel free to shoot me an email, or you can find me on ravelry, facebook or twitter.