I used to sell pot all the time in high school and occasionally, we would run into this. Although, I don't remember an actual stick in the middle. The stuff I always got was just a giant bud wrapped with some kind of real thin string. Almost fishing line. The "stick" in the middle was actually the stem of the bud. Each bud weighed about a 1/4 oz. Maybe a little less.
This stuff sold so well, we used to take all the big buds out of our regular brick weed and wrap it with fishing line and sell it as Thai Stick. LMAO
I definitely remember the "white line" hash. Black as black could be with little layers of opium in between. Awesome stuff. We used to call it "Beef". LOL