@old_hippie There is no slightly sour smell from the residue on the part that had the glue on it after pouring some, if it's not wiped. It solved a non-problem, especially in households with a lot of milk drinkers.
I was in the other kind.
"Ew."
"Ew what? There is nothing wrong with the milk."
"It smells funny."
"That's just the carton."
"I don't want it."
That's all I remember of life before the plastic tube and cap. I was the "ew" kid. Milk slides off of the plastic. The roughness of the carton where the glue was is the culprit.