I understand the bleach and fixer idea, but I see it differently. Green shadows can come from developer temperature shifts. Check your developer before changing the bleach.
Classic C-41 issue right there. The green shadows often point to a bleach or fixer problem, not just temperature. Those chemicals get exhausted FAST if you're reusing them. Make sure your bleach is fully replenished and agitated properly. Also, SCANNER settings can introduce a cast if you're not careful with color correction. Stick with it, though. Dialing in C-41 is a journey, but you're on the right track.