Gibran said:
ditch the photo flo if you wish and instead just use a tiny drop of liquid dish washing detergent in water to make your own photo flo. At least thats what an old RIT instructor once told me and he seemed to know of what he spoke. all you are doing is making a wetting agent to minimize streaks and spots on the film when drying. For some reason, I was once told not to use distilled water alone as a rinse.
That old RIT instructor was WRONG!
The chemical structure is generically right as one type of surfactant but ...
That is a myth and I have posted information here and elsewhere and am trying to stop the continuing spread of that information. The scent and color added along with a lot of other things in any commercial washing detergent will leave an oily residue on film!
Unless the detergent is unscented and uncolored it is unsafe to use with your precious film! The detergent should also be non-ionic for best results, otherwise it can cause a soap film to form on the surface of the emulsion as it will react with calcium ion in water and form a scum just like the soap scum you see in your bath or shower.
Another potential myth is that distilled water can be used as a wash or final rinse to leave film clear of drying defects.
To be exact about it, the water must also be DEIONIZED to remove any crud that has gotten into the distilled water from the metal pipes of the distillation equipment. This is generally not a problem, but I have seen it happen in some instances with dirty, corroded distillation equipment. You must test the quality of your DW first before you can use it flatly without exception.
The DW should also be filtered, as some distillation devices tend to accumulate fungus growths and bacteria that can contaminate the DW with small threads and floaters. These can show up on film just like dust. Sometimes, being so small, they cannot be seen until you try to make an enlargement.
So, this isn't a simple matter. No absolutes. Take some advice from one who has learned this from a technical standpoint and beware of all of the potential pitfalls. Don't fall for hearsay or guesses.
PE