I dont trust oil flush, as its thinner then oil to begin with, let alone once it gets hot!

A mate once ran with this oil flush and his engine sounded like a knitting machine! that was enough to convince me not to use the stuff. But thats just my opinion.

Do an oil and filter change, then another in say, 5000miles/6 months time, which ever is first and see how the oil is then.

The first oil change will help to remove any sludge or deposits already in the engine, not that modern engine suffer too much from sludge etc due to most oils being of decent quality!