Stu Ritter, a 30 yr. MB vet from the Ritter-Easley list has made mention of this approach more than once. He favors it over "snake oil" solutions.

The service mgr. at the independent facility I bought mine from used in '97 told me to not pamper the car or else it would require more service. I do not abuse my MB, but do "open it up" on the highway once fully warmed up periodically. Afterwards, I notice a smoother idle and generally improved performance.

Fortunately the state police haven't noticed. That's the down side to the "Italian Tune Up".