Take your back combed dread and crochet hook.
Small crochet hooks are better, I use a 1mm or smaller.
Put your crochet hook in the dread and snag a small section of hair.
Keep that first loop of hair on your hook and put it back into the dread, snagging another small section of hair.
Pull that second loop through the first loop, leaving you with one loop of hair again on the hook.
Repeat this process down the dread, no need to be neat!
Just snag parts randomly around one side of the dread.
When you reach near the end of the dread, just pull the final loop loose.
Repeat the process of the other side of the dread, pulling in the puffy parts of the dread.
Semi-seal the dread by hanging them up outside or other a bath/sink. And pour boiling water over them.
Leave to dry :)