some people reshape the tip of the pitcher to facilitate the movement of the rosette

because I felt that reshape the tip of the pitcher with the use of forceps to increase or decrease the flow of milk you know something about how to do? for example if you want to decrease the flow of my pitcher as I should model the tip of my pitcher?

hello, I had a question to ask yourself, have you ever tried to reshaping your milk jug ( pitcher) ? if you can explain how to do? Thank you