https://study.com/academy/lesson/what-is-hydrophobic-definition-interactions-quiz.html
So perhaps what is needed is a coating on the bottle that makes the ketchup molecules less attractive, so they repelled, so in theory won't stick.
Such coaching can't be absorbed in to the ketchup either or affect it chemically otherwise those chemicals could end up inside us as people.
Could make an interesting high school research project :D
@zleap I don't know the word for ketchupphobic 😆