Hecate rolled her eyes. "Master Shacklebolt. Wand out please." She said teaching.

She waited until he was following her. "Aim at the... owl.. dung... and cast the Expulso charm. You HAVE learned the Expulso ch-" She shook her head. "Nevermind, it's left strike and jab." She made a striking movement to the left and then jabbing movement and said "Expulso!"

The dung began to bubble and exploded in front of the Slytherin girl. "Expulso uses pressure to make the explosion, as opposed to Confringo, which uses heat. So now you try Master Shaklebolt."