Does dread wax glue hair in place and prevent dreading? - Dreadlocks FAQ's
Oh snap, sounds like you've met a Lock Blocker! They love that line. =]
The short answer is no, Dread Wax helps dreads compress and lock faster. Lock Blockers believe, or pretend to believe, that wax prevents ALL movement between hair strands in a dread. They repeat over and over that dread wax works like glue. Apparently hey think it dries, and gets hard, like glue. The only way they could honestly be mistaken about this is if they've never used dread wax. The truth is, dread wax is nothing like glue and glue is a completely unacceptable substitute for Dread Wax.
In fact our wax never dries out and hardens like glue, even if you leave the lid off of the jar...forever. It always remains pliable. In my bathroom drawer I have an open jar of wax. (In case you're wondering why I still keep wax handy, I use a dab ever once in a while after I pull in a dread ball of loose hair. I put a little on the dread right before I palm roll it and it locks the dread ball in wicked fast. Other than that I haven't used it since my dreads locked up years ago.) Anyway, this jar has been open, in my drawer for years. It's still feels exactly like it did the first day I opened it. DreadHead Dread Wax never dries out or gets hard, we guarantee it.
Wax does slow movement, but it never, ever prevents movement. The first time you put wax in a dread and palm roll it, it's very obvious that the hair can still move around.
The big difference between waxed and unwaxed dreads is that the hair in a waxed dread only moves when a force (like palm rolling or like your head rolling around on your pillow) acts on it. Otherwise it moves very little. This is actually super important - it's the reason the wax can benefit locking the way it does.
Lock Blockers think it's necessary that hair be able to move freely all the time in order for it to lock. This simply isn't true. After you've created knots with backcombing you want the hair in those knots to move in only one direction - tighter. Backing out of the knots (Loosening) is never a benefit. By slowing the movement of the hair in between maintenance sessions when you are not compressing it - and by allowing it to move when you palm roll to tighten and compress the knots, you are helping the dreads progress and tighten faster than they otherwise could. Progress is made while less progress is lost = WIN.
This isn't rocket science but it takes some thought to understand. Saying "Wax dont wurk cuz it stickz yur hair tgether like glew" is a much easier concept to get across...unfortunately it's also completely bunk.
For more info on exactly how wax helps knots tighten check out this FAQ.