If you look at the studies , they did try 2, 4 and 6% . They mentioned that no one had side effects. I used the equivalent of 6% and had no side effects, nothing even near finasteride .
The reason I tried Fluridl is that I had sides effects on dutasteride, and wanted to see if high dosages of flurdil could replace dutasteride. I tried it for a few months and hair got worse, thinner and heading for the even worse. Too bad, because it gave me zero side effects.
The drug is designed to break in blood 10% is not that much, and I am pretty sure that even if the drug was NOT designed to break up in blood, its effect is so weak that you run no risk of chemically castrating yourself... your only risk is loosing more hair over time
Bottom line, fluridil is a very weak anti androgen at best, similar to topical spironolactone where you need very high concentrations to see some very minor effect, which 20 years ago was of some benefit to us.
Today with CB much better potential, it makes no sense to go back in time reviving those old failed drugs, unless you plan to make money out of it. CB maintains hair, even in the lowest concentrations people maintained hair in the one year study, and I get zero side effects.
Like I wrote, try out your 7 or 10% fluridil on its own for a year, and show us pics it maintained hair and then maybe you have a point.