The best map to use this trick on is Militia. Join a Militia map and play as a Counter-Terrorist. This will give you a closer position to the glitch. When you start, buy a Smoke Grenade. Then, go through the tunnel to the left which leads to the fence and the rocks that make a ladder over the fence. Jump the fence and turn to the left. You will see a rock hill. Go up the hill, but do not jump off. You will see a crack between the rock and the wall. Take out the Smoke Grenade, point straight down in the crack, and throw it. You will hear a crackling, like popcorn. Also in the terrorist spawn point on Miltia, there is a bed. Take a smoke grenade and get on the bed. Look down in the corner of the foot board. Throw the smoke grenade in that crack.