This is a good drill to work on your 3 on 0 zone entry tactics. The drill requires a bit of passing and timing before the players attack the zone which helps to simulate a neutral zone transition or regroup. The focus of the drill prior to the zone entry is the player's timing. Good puck support and timing is key to the neutral zone and the players are asked to stay below the puck when receiving passes from the players along the wall.
Four lines get placed at each blue line along the wall with pucks. In the diagram the players are labeled P1, P2, P3, and P4 for this repetition however on the next repetition the players would be labeled opposite so they can attack the other net.
To start the drill P1 makes a pass across the ice to P2 and skates back into the zone before coming back up through the middle of the ice. This is to encourage timing and staying below the puck. The pass back to P1 from P2 should be more horizontal than vertical. P1 will receive the pass and make another pass right away to P3, again they will swing deep into the other zone and face the puck the entire time. P3 will make a pass across the ice to P4 and also swing deep into the zone. P3 will actually allow P1 to get up ice slightly ahead of them and they will provide god support to P4 for the next pass. P3 receives the pass from P4 and then they should be able to head man the puck to P1 to begin attacking the zone. P2 will also join the play as the weak side forward. After the pass they made to P1 they will stay on the weak side to the outside of the dots. Their timing should allow them to be even with P3 when they receive a pass back from P4.
At this point you can emphasize what you want to do with your team on the 3 on 0 rush. It may help to start incorporating coaches as soft defenders or add defense to create 3 vs 1 or 3 vs 2 situations.