First, you may be confusing washing aid and wetting agent. Photo-Flo is a wetting agent, which helps water dry off the film without spots. Washing aid, like Ilford Washaid, Kodak HCA, Berg Bath, etc., helps to neutralize remaining fixer while washing so that wash times are reduced. Neither wash aid nor wetting agent have to be used in C-41 processing.
After your fix or blix step, wash film with water continuously for at least three minutes, then stabilize for a minute and a half to two minutes. It should be the last thing to touch the film. It has a wetting agent in it already, so nothing further is needed.