cleaner for inside the engine or outside?

I use this Gunk Foamy cleaner for outside of the engine to clean up the grease.  It is foamy.  So, I can see where had been sprayed. 

https://www.autozone.com/fuel-and-engine-cleaners-additives/engine-degreaser/p/gunk-engine-cleaner-17oz/523340_0_0

I have used Seafoam in the gas tank of my old car. 

I found the seafoam spray on the internet.  It is a carb cleaner.