After watching some one scrub off 1/4 inch of dirt and rock off his truck (no water just straight to the brush) then his little boy using the brush to clean the bay floor I've never used those on paint. Wheels, tires, bed, tent cover and cab rack get the brush.
I go to a car wash, use the foam, while that loosens everything up I fill my own bucket with soap, hit the truck with high pressure soap. Then hand clean, wipe down with a ceramic wax hybrid, rinse that with the high pressure wax and hand dry. Then the interior and tire shine.
Takes about 2 hours so I usually go after 9pm.