Should I have my Honda Jazz's engine flushed during its service?

My two-year-old Jazz is booked in for its second service this week, and Johnson's Honda in Slough have recommended the engine should be flushed. The car has done 15,000 miles of mixed motoring. What do you think?
The AA says okay for a relatively new engine, not okay for an older engine where it might dislodge carbon deposits and block an oilway. I worry that any residue of the flush remaining in the engine after the drain will contaminate the fresh oil, reducing its lubricity.
Answered by Honest John on

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