Wow - what a jerk. I'd contact the zone rep and report him. Also, a plugged trap will kill power AND reduce MPG significantly. Even a clean, new trap will reduce MPG by 5-10% compared to NO trap. Anyway, here's link to some trap oxidizer documents that Mercedes probably doesn't want you to see (at the bottom, in PDF format):
http://www.meimann.com/docs/mercedes/
Let us know what happens!
Regards,