engine flushing

[magic]

One or two local garages are offering engine flushing. My local mechanic told me not to do it as the sludge may get stuck inside and my Expy is fuel injected and does not need this
Whats this engine flushing, they are talking about?
Any info would be apprciated.

thank you

 

[pronstar]

Save your dough.
So long as you change your oil as recommended, you'll be fine.