Advice vs pros and cons of engine flush

If you want to clean an engine, be careful using an additive, especially if it contains solvents. It could wash lube off surfaces causing damage. Maybe you have little to lose if you're trying to save an engine on its last legs. But if it's a good engine there are very effective oils designed to clean engines.

One is Valvoline Restore. It was discontinued for awhile, but has been reintroduced. It used to be readily available at Cummins dealers and parts centers. I don't know about now.
Premium Blue Restore
Another is HPL, and is what I would use. Less expensive and reported to be very effective. Did I say less expensive? :)
Engine Cleaner