I have NEVER had photo-flo scratch any negatives... The only scratches I've ever had is carelessness when loading the roll of film in the can with the light trap door closed, when I should have it open when spooling.. Oops! Don't make that mistake often, or at all really anymore, but previously I had..
The only Fixer I use is Ilford-Rapid fixer.. Simply because I like Ilford! I will support that company, far more then the nonesense that Kodak has decided to do! Jerks filing for Bankruptcy protection.. (sort of)..