FWIW the only
aerosol foam degreaser that that I've settled on for engine bay maintenance is the Gunk "ORIGINAL" Engine Degreaser (and VERY specifically that aerosol only!!!!). Too often engine degreaser products are NASTY stuff, when coming into contact with paint or some plastics they WILL degrade them. That Gunk product will not. And yet does an outstanding job of cleaning the area you spray it on.
Just use your head, don't go spraying it all over (top of the engine) everything under the hood. I prefer the areas most grungy, usually on the sides of the engine and the bottom. I'll go in there with it on a semi annual basis. Simply spray the product where you want, let it soak, gently hose it off, then maybe take the truck for a few easy laps around the block to dry it all out. FYI, you WILL leave a nasty mess under the vehicle you just sprayed and rinsed this stuff off of. Personally I'd never do all this is right in my own driveway, just a recommendation.