I do the Simple Green deal with the garden hose.
One other thing I do is I go over the cast iron and unprotected metal parts from time to time with CRC corrosion inhibitor to keep everything from rusting. I especially recommend coating all the brake fittings in the front wheel wells with this stuff if you ever want to be abe to service them down the road.

 

Gunk Engine Cleaner ... spray on ... let it sit for few min ... and a hose off ... been doing it this way for 20 years and never a problem. Start the truck right away and let it dry itself.
I will say these Dodges are more work to keep clean than the Chevys I've owned ... there are more and bigger gaps everywhere.