Engine Flush

[Rotary]

Getting the Penrire Sin oil put into my engine tomorrow.
penrite Technical recommended that I put a detergent based engine flush in the old oil first and not use a solvent based flush.
He recommended Sonax or said he thought Valvoline did one, think that is branded Pyroil.
The guy was a technical bloke and did not sound like he was just trying to seel me something He did recommend his competitors product if I could not get Sonax.
Can only find Nulon, Wynns or Lucas which apparently are all solvent based.
Question
Do I need to use an engine flush, does anybody know why a solvent based one should not be used, if Wynns , Nulon etc. are selling them you would think there would be bad publicity if they damaged engines.

I Doubt they will damage engines, because it most likely does very little,

and is not realy a strong detergent,

I would say its totally unnecesary in a regular serviced engine, as the new oil and filter is the best detergent for your engine, so to speak.

[Steampunk]

I can't see anything wrong with solvent-based flushes. Wynns and Lucas have been around for decades and are well respected. You don't survive that long if you make things that doesn't work properly.

[JBT]

Question
Do I need to use an engine flush,...

I've never used one. Unnecessary IMHO.

Wynns and Lucas have been around for decades and are well respected.

The only thing that Lucas made that didn't suck....was a vacuum cleaner.