I responded in your other thread, but I don't think you want to sanitize the day before you make your batch. You should re-sanitize, in my opinion.
Rinse that film off, and then mix up a new batch of one-step. Use one gallon water and 1 tablespoon one-step, and mix very well to dissolve. Swirl to cover all surfaces, and then pour over the cap and airlock.
One-step isn't technically a sanitizer but it does sanitize so don't worry. I like iodophor or star-san, or even crushed campden tablets, since they are "wet contact, no rinse" sanitizers. That means you use the item while still wet with the sanitizer, and you don't let it dry. That's good because it's sanitizing as long as it's wet.