Why would you think that synthetic oil functions as a detergent? It's simply a lubricant with more robust qualities.

 

If you do a search on the DF, check out the guys that have run dino oils in their 4.7 for a long period of time, then decided to change to synthetic engine oil. All the wax and sludge comes to the pan all at once and plugs their inlet screen.

The synthetics are not only good at lubricating, and lasting longer, they keep the inside of your engine, near spotless.