Finding trouble with the tetrapack cartons that store juice, milk etc when you pour them through the spout of the can? Is is spilling randomly and splash out of the carton?

Make two holes on one side of the cap and pour from other side of the cap. This allows air to flow in and push the liquid evenly instead of the random spillage from the temporary vacuum created in the carton.

Alternatively if you prefer not to damage the bottle, and if your carton has an off centered spout try pouring it with the spout at the top so air can get to the top of the bottle. Similar to the way you pour water out of a motor oil can.

(AW- Anil)