Back 50 years ago, when film and Kodak were still king, the technical magazines generally recommended that Photoflo 200 be diluted for use at 400:1, half the strength of the Kodak recommendation. The basis was that used as recommended, the working solution was strong enough to scum the film if used without care, and that it tended to take longer to dry. In any event, I've used the weaker dilution for about half a century with no issues. I have no data on drying time, as I never use a wipe or squeegee, but just mix with distilled water, dunk film for 30 seconds and hang to dry in a drying cabinet. Perfect results every time. I do not understand why everyone doesn't use the stuff or equivalent as a matter of course. Since I tend to save up shot rolls until I have the motivation to develop the accumulated batch in one session, I just mix a working solution for each session and toss it at conclusion. As you note, it is cheaper than dirt.

So glad The Photoshop stocks these Yoshiko Hake brushes!

Thanks! Very welcome info.

man, you are seriously over thinking this.... general rule of thumb by all labs is 2 drops per roll of film. there is no need to be any more specific than that honestly. and disposal? meh, just toss it down the drain. its not hazardous in any way when diluted.