Red Max Pro & ZEP cleaning question

I did the ZEP treatment a little over a year ago and my rig still shines like new money when it's clean.

Any of you fellow ZEP/RMPusers have a good go to cleaner for black streaks?

I found out today one NOT to use- Mean Green from walmart- I dulled up a nice sized place in my effort to remove the black streaks. Guess I'll have to go back and reapply the ZEP

Thanks in advance.