It depends on how soiled the dash is, but typically a few drops of any pH-neutral soap like Woolite diluted in some warm water is enough. I haven't had to clean anything worse than dust off of the dash, but if it had fingerprints, food or drink on it, that's what I would use. IMO, no reason to spend money on something like Cockpit Premium when you can basically make the same thing with stuff you have at home, unless you like the smell.
Personally, I use a Swiffer duster to remove the dust, then spray 303 Aerospace Protectant onto a microfiber cloth and wipe down everything except the windshield glass, the Infotainment screen, and the instrument display. Dash stays clean, and I also have an extra layer of UV protection that adds richness to the colour, is dry to the touch, and is not shiny or greasy.
It's not a great picture, but here's a side by side comparison. The left side has been wiped down with 303. Right side has nothing on it.