16 oz of PhotFlo will last a long time. What sort of clips will you use to hang the film, and is the location still air?

The first few time you do this, use a written check list and tick it off as you go. Label the solutions. I prefer to use a stop clock or a kitchen clock with a second hand for timing - easier to keep an eye on while I am tidying up. But then my phone won't run apps.