You can make Factory Sealed Impromptu.
Others have posted where they have literally done the secret right in front of specs at a crowded ball game. No one is watching you, they are watching the game. To the specs it is pure magic because you just bought the bottle.
It even says on the product page under FAQs where you can do it right out of a vending machine. You have to structure your routine around it.
By the time you turn around after getting it out of the vending maching you can be ready to go, it's that easy and that practical. No one is expecting anything at that point. You are just getting a drink.
I agree with that Infusion isn't as powerful.
Even though you can pick up and go with it, the fact that the container is open and done too fast isn't as impressive as a slow penetration in an unopened bottle with a borrowed coin. The fact that no gimmicks are used is great though because you don't need to carry anything around with you. Nothing to rely on.